Bump v9.0.0-beta.1

Revert "Bump v9.0.0-beta.2"
This reverts commit 74d4dab157.
2026-04-10 03:01:51 -04:00 · 2020-02-10 06:50:08 -08:00 · 2020-02-10 06:38:44 -08:00 · 2020-02-10 04:32:41 -08:00 · 2020-02-10 17:09:35 +09:00 · 2020-02-10 17:05:34 +09:00
1272 changed files with 36564 additions and 26612 deletions
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -17,18 +17,29 @@
    "prefer-const": ["error", {
      "destructuring": "all"
    }],
+    "standard/no-callback-literal": "off",
    "node/no-deprecated-api": 0
  },
  "parserOptions": {
    "ecmaVersion": 6,
    "sourceType": "module"
  },
+  "globals": {
+    "standardScheme": "readonly"
+  },
  "overrides": [
    {
      "files": "*.js",
      "rules": {
          "@typescript-eslint/no-unused-vars": "off"
      }
+    },
+    {
+      "files": "*.d.ts",
+      "rules": {
+          "no-useless-constructor": "off",
+          "@typescript-eslint/no-unused-vars": "off"
+      }
    }
  ]
 }
--- a/.github/ISSUE_TEMPLATE/security_report.md
+++ b/.github/ISSUE_TEMPLATE/security_report.md
@@ -1,10 +0,0 @@
---
-name: Security report
-about: Do not create an issue for security reports, send an email to security@electronjs.org
-
---
-
-### Notice 
-
-**DO NOT** create an issue for security reports.
-Send an email to: **security@electronjs.org**.
--- a/.github/config.yml
+++ b/.github/config.yml
@@ -29,13 +29,11 @@ firstPRMergeComment: >
 # Users authorized to run manual trop backports
 authorizedUsers:
  - alexeykuzmin
-  - BinaryMuse
  - ckerr
  - codebytere
  - deepak1556
  - jkleinsc
  - MarshallOfSound
  - miniak
-  - nitsakh
  - nornagon
  - zcbenz
--- a/.gitignore
+++ b/.gitignore
@@ -58,10 +58,11 @@ spec/.hash
 .eslintcache

 # Generated native addon files
-/spec/fixtures/native-addon/echo/build/
+/spec-main/fixtures/native-addon/echo/build/

 # If someone runs tsc this is where stuff will end up
 ts-gen

 # Used to accelerate CI builds
 .depshash
+.depshash-target
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -1,9 +1,12 @@
 import("//build/config/locales.gni")
 import("//build/config/ui.gni")
 import("//build/config/win/manifest.gni")
+import("//components/spellcheck/spellcheck_build_features.gni")
 import("//content/public/app/mac_helpers.gni")
 import("//pdf/features.gni")
+import("//ppapi/buildflags/buildflags.gni")
 import("//printing/buildflags/buildflags.gni")
+import("//testing/test.gni")
 import("//third_party/ffmpeg/ffmpeg_options.gni")
 import("//tools/generate_library_loader/generate_library_loader.gni")
 import("//tools/grit/grit_rule.gni")
@@ -20,12 +23,14 @@ import("buildflags/buildflags.gni")
 import("electron_paks.gni")
 import("filenames.auto.gni")
 import("filenames.gni")
+import("filenames.hunspell.gni")

 if (is_mac) {
  import("//build/config/mac/rules.gni")
  import("//third_party/icu/config.gni")
  import("//ui/gl/features.gni")
  import("//v8/gni/v8.gni")
+  import("build/rules.gni")
 }

 if (is_linux) {
@@ -60,6 +65,10 @@ config("branding") {
  ]
 }

+config("electron_lib_config") {
+  include_dirs = [ "." ]
+}
+
 # We geneate the definitions twice here, once in //electron/electron.d.ts
 # and once in $target_gen_dir
 # The one in $target_gen_dir is used for the actual TSC build later one
@@ -70,15 +79,11 @@ npm_action("build_electron_definitions") {
  args = [ rebase_path("$target_gen_dir/tsc/typings/electron.d.ts") ]
  inputs = auto_filenames.api_docs + [ "yarn.lock" ]

-  outputs = [
-    "$target_gen_dir/tsc/typings/electron.d.ts",
-  ]
+  outputs = [ "$target_gen_dir/tsc/typings/electron.d.ts" ]
 }

 webpack_build("electron_browser_bundle") {
-  deps = [
-    ":build_electron_definitions",
-  ]
+  deps = [ ":build_electron_definitions" ]

  inputs = auto_filenames.browser_bundle_deps

@@ -87,9 +92,7 @@ webpack_build("electron_browser_bundle") {
 }

 webpack_build("electron_renderer_bundle") {
-  deps = [
-    ":build_electron_definitions",
-  ]
+  deps = [ ":build_electron_definitions" ]

  inputs = auto_filenames.renderer_bundle_deps

@@ -98,9 +101,7 @@ webpack_build("electron_renderer_bundle") {
 }

 webpack_build("electron_worker_bundle") {
-  deps = [
-    ":build_electron_definitions",
-  ]
+  deps = [ ":build_electron_definitions" ]

  inputs = auto_filenames.worker_bundle_deps

@@ -109,9 +110,7 @@ webpack_build("electron_worker_bundle") {
 }

 webpack_build("electron_sandboxed_renderer_bundle") {
-  deps = [
-    ":build_electron_definitions",
-  ]
+  deps = [ ":build_electron_definitions" ]

  inputs = auto_filenames.sandbox_bundle_deps

@@ -120,9 +119,7 @@ webpack_build("electron_sandboxed_renderer_bundle") {
 }

 webpack_build("electron_isolated_renderer_bundle") {
-  deps = [
-    ":build_electron_definitions",
-  ]
+  deps = [ ":build_electron_definitions" ]

  inputs = auto_filenames.isolated_bundle_deps

@@ -131,9 +128,7 @@ webpack_build("electron_isolated_renderer_bundle") {
 }

 webpack_build("electron_content_script_bundle") {
-  deps = [
-    ":build_electron_definitions",
-  ]
+  deps = [ ":build_electron_definitions" ]

  inputs = auto_filenames.content_script_bundle_deps

@@ -141,22 +136,20 @@ webpack_build("electron_content_script_bundle") {
  out_file = "$target_gen_dir/js2c/content_script_bundle.js"
 }

-copy("atom_js2c_copy") {
+copy("electron_js2c_copy") {
  sources = [
    "lib/common/asar.js",
    "lib/common/asar_init.js",
  ]
-  outputs = [
-    "$target_gen_dir/js2c/{{source_file_part}}",
-  ]
+  outputs = [ "$target_gen_dir/js2c/{{source_file_part}}" ]
 }

-action("atom_js2c") {
+action("electron_js2c") {
  deps = [
-    ":atom_js2c_copy",
    ":electron_browser_bundle",
    ":electron_content_script_bundle",
    ":electron_isolated_renderer_bundle",
+    ":electron_js2c_copy",
    ":electron_renderer_bundle",
    ":electron_sandboxed_renderer_bundle",
    ":electron_worker_bundle",
@@ -164,11 +157,11 @@ action("atom_js2c") {

  webpack_sources = [
    "$target_gen_dir/js2c/browser_init.js",
-    "$target_gen_dir/js2c/renderer_init.js",
-    "$target_gen_dir/js2c/worker_init.js",
    "$target_gen_dir/js2c/content_script_bundle.js",
    "$target_gen_dir/js2c/isolated_bundle.js",
+    "$target_gen_dir/js2c/renderer_init.js",
    "$target_gen_dir/js2c/sandbox_bundle.js",
+    "$target_gen_dir/js2c/worker_init.js",
  ]

  sources = webpack_sources + [
@@ -177,9 +170,7 @@ action("atom_js2c") {
            ]

  inputs = sources + [ "//third_party/electron_node/tools/js2c.py" ]
-  outputs = [
-    "$root_gen_dir/atom_natives.cc",
-  ]
+  outputs = [ "$root_gen_dir/electron_natives.cc" ]

  script = "tools/js2c.py"
  args = [ rebase_path("//third_party/electron_node") ] +
@@ -190,9 +181,7 @@ action("atom_js2c") {
 target_gen_default_app_js = "$target_gen_dir/js/default_app"

 typescript_build("default_app_js") {
-  deps = [
-    ":build_electron_definitions",
-  ]
+  deps = [ ":build_electron_definitions" ]
  type_root = rebase_path("$target_gen_dir/tsc/electron/typings")

  sources = filenames.default_app_ts_sources
@@ -204,16 +193,12 @@ typescript_build("default_app_js") {

 copy("default_app_static") {
  sources = filenames.default_app_static_sources
-  outputs = [
-    "$target_gen_default_app_js/{{source}}",
-  ]
+  outputs = [ "$target_gen_default_app_js/{{source}}" ]
 }

 copy("default_app_octicon_deps") {
  sources = filenames.default_app_octicon_sources
-  outputs = [
-    "$target_gen_default_app_js/electron/default_app/octicon/{{source_file_part}}",
-  ]
+  outputs = [ "$target_gen_default_app_js/electron/default_app/octicon/{{source_file_part}}" ]
 }

 asar("default_app_asar") {
@@ -227,9 +212,7 @@ asar("default_app_asar") {
  sources = get_target_outputs(":default_app_js") +
            get_target_outputs(":default_app_static") +
            get_target_outputs(":default_app_octicon_deps")
-  outputs = [
-    "$root_out_dir/resources/default_app.asar",
-  ]
+  outputs = [ "$root_out_dir/resources/default_app.asar" ]
 }

 grit("resources") {
@@ -247,20 +230,14 @@ grit("resources") {
    "target_gen_dir=" + rebase_path(target_gen_dir, root_build_dir),
  ]

-  deps = [
-    ":copy_shell_devtools_discovery_page",
-  ]
+  deps = [ ":copy_shell_devtools_discovery_page" ]

  output_dir = "$target_gen_dir"
 }

 copy("copy_shell_devtools_discovery_page") {
-  sources = [
-    "//content/shell/resources/shell_devtools_discovery_page.html",
-  ]
-  outputs = [
-    "$target_gen_dir/shell_devtools_discovery_page.html",
-  ]
+  sources = [ "//content/shell/resources/shell_devtools_discovery_page.html" ]
+  outputs = [ "$target_gen_dir/shell_devtools_discovery_page.html" ]
 }

 if (is_linux) {
@@ -280,6 +257,7 @@ if (is_linux) {
      "notify_notification_add_action",
      "notify_notification_set_image_from_pixbuf",
      "notify_notification_set_timeout",
+      "notify_notification_set_urgency",
      "notify_notification_set_hint_string",
      "notify_notification_show",
      "notify_notification_close",
@@ -305,9 +283,7 @@ source_set("manifests") {
 npm_action("electron_version_args") {
  script = "generate-version-json"

-  outputs = [
-    "$target_gen_dir/electron_version.args",
-  ]
+  outputs = [ "$target_gen_dir/electron_version.args" ]

  args = rebase_path(outputs)

@@ -318,9 +294,7 @@ npm_action("electron_version_args") {
 }

 templated_file("electron_version_header") {
-  deps = [
-    ":electron_version_args",
-  ]
+  deps = [ ":electron_version_args" ]

  template = "build/templates/electron_version.tmpl"
  output = "$target_gen_dir/electron_version.h"
@@ -332,28 +306,32 @@ source_set("electron_lib") {
  configs += [ "//v8:external_startup_data" ]
  configs += [ "//third_party/electron_node:node_internals" ]

-  public_configs = [ ":branding" ]
+  public_configs = [
+    ":branding",
+    ":electron_lib_config",
+  ]

  deps = [
-    ":atom_js2c",
+    ":electron_js2c",
    ":electron_version_header",
    ":manifests",
    ":resources",
    "buildflags",
    "chromium_src:chrome",
-    "native_mate",
+    "chromium_src:chrome_spellchecker",
    "shell/common/api:mojo",
    "//base:base_static",
    "//base/allocator:buildflags",
    "//chrome/app/resources:platform_locale_settings",
    "//chrome/services/printing/public/mojom",
    "//components/certificate_transparency",
+    "//components/language/core/browser",
    "//components/net_log",
-    "//components/network_hints/common",
+    "//components/network_hints/browser",
+    "//components/network_hints/common:mojo_bindings",
    "//components/network_hints/renderer",
    "//components/network_session_configurator/common",
    "//components/prefs",
-    "//components/spellcheck/renderer",
    "//components/viz/host",
    "//components/viz/service",
    "//content/public/browser",
@@ -369,12 +347,10 @@ source_set("electron_lib") {
    "//media/mojo/mojom",
    "//net:extras",
    "//net:net_resources",
-    "//net:net_with_v8",
    "//ppapi/host",
    "//ppapi/proxy",
    "//ppapi/shared_impl",
    "//printing/buildflags",
-    "//services/audio/public/mojom:constants",
    "//services/device/public/cpp/geolocation",
    "//services/device/public/mojom",
    "//services/proxy_resolver:lib",
@@ -386,7 +362,7 @@ source_set("electron_lib") {
    "//third_party/electron_node:node_lib",
    "//third_party/leveldatabase",
    "//third_party/libyuv",
-    "//third_party/webrtc_overrides:init_webrtc",
+    "//third_party/webrtc_overrides:webrtc_component",
    "//third_party/widevine/cdm:headers",
    "//ui/base/idle",
    "//ui/events:dom_keycode_converter",
@@ -474,12 +450,25 @@ source_set("electron_lib") {
      "//content/common:mac_helpers",
      "//ui/accelerated_widget_mac",
    ]
+
+    libs = [
+      "AVFoundation.framework",
+      "Carbon.framework",
+      "LocalAuthentication.framework",
+      "QuartzCore.framework",
+      "Quartz.framework",
+      "Security.framework",
+      "SecurityInterface.framework",
+      "ServiceManagement.framework",
+      "StoreKit.framework",
+    ]
+
    sources += [
      "shell/browser/ui/views/autofill_popup_view.cc",
      "shell/browser/ui/views/autofill_popup_view.h",
    ]
    if (is_mas_build) {
-      sources += [ "shell/browser/api/atom_api_app_mas.mm" ]
+      sources += [ "shell/browser/api/electron_api_app_mas.mm" ]
      sources -= [
        "shell/browser/auto_updater_mac.mm",
        "shell/common/crash_reporter/crash_reporter_mac.h",
@@ -505,7 +494,7 @@ source_set("electron_lib") {
    deps += [
      ":libnotify_loader",
      "//build/config/linux/gtk",
-      "//chrome/browser/ui/libgtkui",
+      "//chrome/browser/ui/gtk",
      "//dbus",
      "//device/bluetooth",
      "//third_party/breakpad:client",
@@ -523,6 +512,10 @@ source_set("electron_lib") {
    ]

    sources += filenames.lib_sources_nss
+    sources += [
+      "shell/browser/ui/gtk_util.cc",
+      "shell/browser/ui/gtk_util.h",
+    ]
  }
  if (is_win) {
    libs += [ "dwmapi.lib" ]
@@ -546,8 +539,12 @@ source_set("electron_lib") {
    deps += [ "//third_party/crashpad/crashpad/client" ]
  }

-  if (enable_pdf) {
-    deps += [ "//pdf" ]
+  if (enable_plugins) {
+    deps += [ "chromium_src:plugins" ]
+    sources += [
+      "shell/renderer/pepper_helper.cc",
+      "shell/renderer/pepper_helper.h",
+    ]
  }

  if (enable_run_as_node) {
@@ -579,6 +576,17 @@ source_set("electron_lib") {
    ]
  }

+  if (enable_remote_module) {
+    sources += [
+      "shell/common/api/remote/object_life_monitor.cc",
+      "shell/common/api/remote/object_life_monitor.h",
+      "shell/common/api/remote/remote_callback_freer.cc",
+      "shell/common/api/remote/remote_callback_freer.h",
+      "shell/common/api/remote/remote_object_freer.cc",
+      "shell/common/api/remote/remote_object_freer.h",
+    ]
+  }
+
  if (enable_desktop_capturer) {
    if (is_component_build && !is_linux) {
      # On windows the implementation relies on unexported
@@ -587,27 +595,27 @@ source_set("electron_lib") {
      deps += [ "//third_party/webrtc/modules/desktop_capture" ]
    }
    sources += [
-      "shell/browser/api/atom_api_desktop_capturer.cc",
-      "shell/browser/api/atom_api_desktop_capturer.h",
+      "shell/browser/api/electron_api_desktop_capturer.cc",
+      "shell/browser/api/electron_api_desktop_capturer.h",
    ]
  }

  if (enable_view_api) {
    sources += [
-      "shell/browser/api/views/atom_api_box_layout.cc",
-      "shell/browser/api/views/atom_api_box_layout.h",
-      "shell/browser/api/views/atom_api_button.cc",
-      "shell/browser/api/views/atom_api_button.h",
-      "shell/browser/api/views/atom_api_label_button.cc",
-      "shell/browser/api/views/atom_api_label_button.h",
-      "shell/browser/api/views/atom_api_layout_manager.cc",
-      "shell/browser/api/views/atom_api_layout_manager.h",
-      "shell/browser/api/views/atom_api_md_text_button.cc",
-      "shell/browser/api/views/atom_api_md_text_button.h",
-      "shell/browser/api/views/atom_api_resize_area.cc",
-      "shell/browser/api/views/atom_api_resize_area.h",
-      "shell/browser/api/views/atom_api_text_field.cc",
-      "shell/browser/api/views/atom_api_text_field.h",
+      "shell/browser/api/views/electron_api_box_layout.cc",
+      "shell/browser/api/views/electron_api_box_layout.h",
+      "shell/browser/api/views/electron_api_button.cc",
+      "shell/browser/api/views/electron_api_button.h",
+      "shell/browser/api/views/electron_api_label_button.cc",
+      "shell/browser/api/views/electron_api_label_button.h",
+      "shell/browser/api/views/electron_api_layout_manager.cc",
+      "shell/browser/api/views/electron_api_layout_manager.h",
+      "shell/browser/api/views/electron_api_md_text_button.cc",
+      "shell/browser/api/views/electron_api_md_text_button.h",
+      "shell/browser/api/views/electron_api_resize_area.cc",
+      "shell/browser/api/views/electron_api_resize_area.h",
+      "shell/browser/api/views/electron_api_text_field.cc",
+      "shell/browser/api/views/electron_api_text_field.h",
    ]
  }

@@ -618,13 +626,11 @@ source_set("electron_lib") {
      "shell/renderer/printing/print_render_frame_helper_delegate.cc",
      "shell/renderer/printing/print_render_frame_helper_delegate.h",
    ]
+    deps += [ "//components/printing/common:mojo_interfaces" ]
  }

-  if (enable_pepper_flash) {
-    deps += [ "components/pepper_flash" ]
-  }
-
-  public_deps += [ "shell/common/extensions/api:extensions_features" ]
+  deps += [ "shell/common/extensions/api:extensions_features" ]
+  deps += [ "shell/common/extensions/api" ]
  deps += [
    "//components/pref_registry",
    "//components/user_prefs",
@@ -637,6 +643,22 @@ source_set("electron_lib") {
  if (enable_electron_extensions) {
    sources += filenames.lib_sources_extensions
  }
+
+  if (enable_pdf) {
+    # Printing depends on some //pdf code, so it needs to be built even if the
+    # pdf viewer isn't enabled.
+    deps += [ "//pdf" ]
+  }
+  if (enable_pdf_viewer) {
+    deps += [
+      "//components/pdf/browser",
+      "//components/pdf/renderer",
+    ]
+    sources += [
+      "shell/browser/electron_pdf_web_contents_helper_client.cc",
+      "shell/browser/electron_pdf_web_contents_helper_client.h",
+    ]
+  }
 }

 electron_paks("packed_resources") {
@@ -655,17 +677,18 @@ if (is_mac) {
  electron_framework_version = "A"
  electron_version = read_file("ELECTRON_VERSION", "trim string")

+  mac_xib_bundle_data("electron_xibs") {
+    sources = [ "shell/common/resources/mac/MainMenu.xib" ]
+  }
+
  bundle_data("electron_framework_resources") {
-    public_deps = [
-      ":packed_resources",
-    ]
+    public_deps = [ ":packed_resources" ]
    sources = []
    if (icu_use_data_file) {
      sources += [ "$root_out_dir/icudtl.dat" ]
      public_deps += [ "//third_party/icu:icudata" ]
    }
    if (v8_use_external_startup_data) {
-      sources += [ "$root_out_dir/natives_blob.bin" ]
      public_deps += [ "//v8" ]
      if (use_v8_context_snapshot) {
        sources += [ "$root_out_dir/v8_context_snapshot.bin" ]
@@ -674,22 +697,16 @@ if (is_mac) {
        sources += [ "$root_out_dir/snapshot_blob.bin" ]
      }
    }
-    outputs = [
-      "{{bundle_resources_dir}}/{{source_file_part}}",
-    ]
+    outputs = [ "{{bundle_resources_dir}}/{{source_file_part}}" ]
  }

-  if (!is_component_build) {
+  if (!is_component_build && is_component_ffmpeg) {
    bundle_data("electron_framework_libraries") {
      sources = []
      public_deps = []
-      if (is_component_ffmpeg) {
-        sources += [ "$root_out_dir/libffmpeg.dylib" ]
-        public_deps += [ "//third_party/ffmpeg:ffmpeg" ]
-      }
-      outputs = [
-        "{{bundle_contents_dir}}/Libraries/{{source_file_part}}",
-      ]
+      sources += [ "$root_out_dir/libffmpeg.dylib" ]
+      public_deps += [ "//third_party/ffmpeg:ffmpeg" ]
+      outputs = [ "{{bundle_contents_dir}}/Libraries/{{source_file_part}}" ]
    }
  } else {
    group("electron_framework_libraries") {
@@ -702,12 +719,8 @@ if (is_mac) {
        "$root_out_dir/egl_intermediates/libEGL.dylib",
        "$root_out_dir/egl_intermediates/libGLESv2.dylib",
      ]
-      outputs = [
-        "{{bundle_contents_dir}}/Libraries/{{source_file_part}}",
-      ]
-      public_deps = [
-        "//ui/gl:angle_library_copy",
-      ]
+      outputs = [ "{{bundle_contents_dir}}/Libraries/{{source_file_part}}" ]
+      public_deps = [ "//ui/gl:angle_library_copy" ]
    }

    # Add the SwiftShader .dylibs in the Libraries directory of the Framework.
@@ -716,42 +729,28 @@ if (is_mac) {
        "$root_out_dir/egl_intermediates/libswiftshader_libEGL.dylib",
        "$root_out_dir/egl_intermediates/libswiftshader_libGLESv2.dylib",
      ]
-      outputs = [
-        "{{bundle_contents_dir}}/Libraries/{{source_file_part}}",
-      ]
-      public_deps = [
-        "//ui/gl:swiftshader_library_copy",
-      ]
+      outputs = [ "{{bundle_contents_dir}}/Libraries/{{source_file_part}}" ]
+      public_deps = [ "//ui/gl:swiftshader_library_copy" ]
    }
  }
  group("electron_angle_library") {
    if (use_egl) {
-      deps = [
-        ":electron_angle_binaries",
-      ]
+      deps = [ ":electron_angle_binaries" ]
    }
  }

  group("electron_swiftshader_library") {
    if (use_egl) {
-      deps = [
-        ":electron_swiftshader_binaries",
-      ]
+      deps = [ ":electron_swiftshader_binaries" ]
    }
  }

  bundle_data("electron_crashpad_helper") {
-    sources = [
-      "$root_out_dir/crashpad_handler",
-    ]
+    sources = [ "$root_out_dir/crashpad_handler" ]

-    outputs = [
-      "{{bundle_resources_dir}}/{{source_file_part}}",
-    ]
+    outputs = [ "{{bundle_resources_dir}}/{{source_file_part}}" ]

-    public_deps = [
-      "//third_party/crashpad/crashpad/handler:crashpad_handler",
-    ]
+    public_deps = [ "//third_party/crashpad/crashpad/handler:crashpad_handler" ]
  }

  mac_framework_bundle("electron_framework") {
@@ -762,6 +761,7 @@ if (is_mac) {
      "Libraries",
    ]
    public_deps = [
+      ":electron_framework_libraries",
      ":electron_lib",
    ]
    deps = [
@@ -769,6 +769,7 @@ if (is_mac) {
      ":electron_framework_libraries",
      ":electron_framework_resources",
      ":electron_swiftshader_library",
+      ":electron_xibs",
    ]
    if (!is_mas_build) {
      deps += [ ":electron_crashpad_helper" ]
@@ -783,18 +784,6 @@ if (is_mac) {
    include_dirs = [ "." ]
    sources = filenames.framework_sources

-    libs = [
-      "AVFoundation.framework",
-      "Carbon.framework",
-      "LocalAuthentication.framework",
-      "QuartzCore.framework",
-      "Quartz.framework",
-      "Security.framework",
-      "SecurityInterface.framework",
-      "ServiceManagement.framework",
-      "StoreKit.framework",
-    ]
-
    if (enable_osr) {
      libs += [ "IOSurface.framework" ]
    }
@@ -819,15 +808,13 @@ if (is_mac) {
      assert(defined(invoker.helper_name_suffix))

      output_name = electron_helper_name + invoker.helper_name_suffix
-      deps = [
-        ":electron_framework+link",
-      ]
+      deps = [ ":electron_framework+link" ]
      if (!is_mas_build) {
        deps += [ "//sandbox/mac:seatbelt" ]
      }
      defines = [ "HELPER_EXECUTABLE" ]
      sources = filenames.app_sources
-      sources += [ "shell/common/atom_constants.cc" ]
+      sources += [ "shell/common/electron_constants.cc" ]
      include_dirs = [ "." ]
      info_plist = "shell/renderer/resources/mac/Info.plist"
      extra_substitutions =
@@ -855,9 +842,7 @@ if (is_mac) {
  }

  bundle_data("electron_app_framework_bundle_data") {
-    sources = [
-      "$root_out_dir/$electron_framework_name.framework",
-    ]
+    sources = [ "$root_out_dir/$electron_framework_name.framework" ]
    if (!is_mas_build) {
      sources += [
        "external_binaries/Mantle.framework",
@@ -865,12 +850,8 @@ if (is_mac) {
        "external_binaries/Squirrel.framework",
      ]
    }
-    outputs = [
-      "{{bundle_contents_dir}}/Frameworks/{{source_file_part}}",
-    ]
-    public_deps = [
-      ":electron_framework+link",
-    ]
+    outputs = [ "{{bundle_contents_dir}}/Frameworks/{{source_file_part}}" ]
+    public_deps = [ ":electron_framework+link" ]

    foreach(helper_params, content_mac_helpers) {
      sources +=
@@ -890,15 +871,10 @@ if (is_mac) {
  }

  bundle_data("electron_login_helper_app") {
-    public_deps = [
-      ":electron_login_helper",
-    ]
-    sources = [
-      "$root_out_dir/$electron_login_helper_name.app",
-    ]
-    outputs = [
-      "{{bundle_contents_dir}}/Library/LoginItems/{{source_file_part}}",
-    ]
+    public_deps = [ ":electron_login_helper" ]
+    sources = [ "$root_out_dir/$electron_login_helper_name.app" ]
+    outputs =
+        [ "{{bundle_contents_dir}}/Library/LoginItems/{{source_file_part}}" ]
  }

  action("electron_app_lproj_dirs") {
@@ -913,15 +889,9 @@ if (is_mac) {

  foreach(locale, locales_as_mac_outputs) {
    bundle_data("electron_app_strings_${locale}_bundle_data") {
-      sources = [
-        "$target_gen_dir/app_infoplist_strings/$locale.lproj",
-      ]
-      outputs = [
-        "{{bundle_resources_dir}}/$locale.lproj",
-      ]
-      public_deps = [
-        ":electron_app_lproj_dirs",
-      ]
+      sources = [ "$target_gen_dir/app_infoplist_strings/$locale.lproj" ]
+      outputs = [ "{{bundle_resources_dir}}/$locale.lproj" ]
+      public_deps = [ ":electron_app_lproj_dirs" ]
    }
  }
  group("electron_app_strings_bundle_data") {
@@ -940,15 +910,13 @@ if (is_mac) {
      "$root_out_dir/resources/default_app.asar",
      "shell/browser/resources/mac/electron.icns",
    ]
-    outputs = [
-      "{{bundle_resources_dir}}/{{source_file_part}}",
-    ]
+    outputs = [ "{{bundle_resources_dir}}/{{source_file_part}}" ]
  }

  mac_app_bundle("electron_app") {
    output_name = electron_product_name
    sources = filenames.app_sources
-    sources += [ "shell/common/atom_constants.cc" ]
+    sources += [ "shell/common/electron_constants.cc" ]
    include_dirs = [ "." ]
    deps = [
      ":electron_app_framework_bundle_data",
@@ -973,9 +941,7 @@ if (is_mac) {
      binary = "$root_out_dir/$electron_framework_name.framework/Versions/$electron_framework_version/$electron_framework_name"
      symbol_dir = "$root_out_dir/breakpad_symbols"
      dsym_file = "$root_out_dir/$electron_framework_name.dSYM/Contents/Resources/DWARF/$electron_framework_name"
-      deps = [
-        ":electron_framework",
-      ]
+      deps = [ ":electron_framework" ]
    }

    foreach(helper_params, content_mac_helpers) {
@@ -986,9 +952,7 @@ if (is_mac) {
        binary = "$root_out_dir/$electron_helper_name${_helper_suffix}.app/Contents/MacOS/$electron_helper_name${_helper_suffix}"
        symbol_dir = "$root_out_dir/breakpad_symbols"
        dsym_file = "$root_out_dir/$electron_helper_name${_helper_suffix}.dSYM/Contents/Resources/DWARF/$electron_helper_name${_helper_suffix}"
-        deps = [
-          ":electron_helper_app_${_helper_target}",
-        ]
+        deps = [ ":electron_helper_app_${_helper_target}" ]
      }
    }

@@ -996,18 +960,15 @@ if (is_mac) {
      binary = "$root_out_dir/$electron_product_name.app/Contents/MacOS/$electron_product_name"
      symbol_dir = "$root_out_dir/breakpad_symbols"
      dsym_file = "$root_out_dir/$electron_product_name.dSYM/Contents/Resources/DWARF/$electron_product_name"
-      deps = [
-        ":electron_app",
-      ]
+      deps = [ ":electron_app" ]
    }

    extract_symbols("swiftshader_egl_syms") {
      binary = "$root_out_dir/libswiftshader_libEGL.dylib"
      symbol_dir = "$root_out_dir/breakpad_symbols"
      dsym_file = "$root_out_dir/libswiftshader_libEGL.dylib.dSYM/Contents/Resources/DWARF/libswiftshader_libEGL.dylib"
-      deps = [
-        "//third_party/swiftshader/src/OpenGL/libEGL:swiftshader_libEGL",
-      ]
+      deps =
+          [ "//third_party/swiftshader/src/OpenGL/libEGL:swiftshader_libEGL" ]
    }

    extract_symbols("swiftshader_gles_syms") {
@@ -1023,9 +984,7 @@ if (is_mac) {
      binary = "$root_out_dir/crashpad_handler"
      symbol_dir = "$root_out_dir/breakpad_symbols"
      dsym_file = "$root_out_dir/crashpad_handler.dSYM/Contents/Resources/DWARF/crashpad_handler"
-      deps = [
-        "//third_party/crashpad/crashpad/handler:crashpad_handler",
-      ]
+      deps = [ "//third_party/crashpad/crashpad/handler:crashpad_handler" ]
    }

    group("electron_symbols") {
@@ -1086,9 +1045,7 @@ if (is_mac) {
      data += [ "$root_out_dir/resources/default_app.asar" ]
    }

-    public_deps = [
-      "//tools/v8_context_snapshot:v8_context_snapshot",
-    ]
+    public_deps = [ "//tools/v8_context_snapshot:v8_context_snapshot" ]

    if (is_win) {
      sources += [
@@ -1145,17 +1102,14 @@ if (is_mac) {
    extract_symbols("electron_app_symbols") {
      binary = "$root_out_dir/$electron_project_name$_target_executable_suffix"
      symbol_dir = "$root_out_dir/breakpad_symbols"
-      deps = [
-        ":electron_app",
-      ]
+      deps = [ ":electron_app" ]
    }

    extract_symbols("swiftshader_egl_symbols") {
      binary = "$root_out_dir/swiftshader/libEGL$_target_shared_library_suffix"
      symbol_dir = "$root_out_dir/breakpad_symbols"
-      deps = [
-        "//third_party/swiftshader/src/OpenGL/libEGL:swiftshader_libEGL",
-      ]
+      deps =
+          [ "//third_party/swiftshader/src/OpenGL/libEGL:swiftshader_libEGL" ]
    }

    extract_symbols("swiftshader_gles_symbols") {
@@ -1177,6 +1131,37 @@ if (is_mac) {
  }
 }

+test("shell_browser_ui_unittests") {
+  sources = [
+    "//electron/shell/browser/ui/accelerator_util_unittests.cc",
+    "//electron/shell/browser/ui/run_all_unittests.cc",
+  ]
+
+  configs += [ ":electron_lib_config" ]
+
+  deps = [
+    ":electron_lib",
+    "//base",
+    "//base/test:test_support",
+    "//testing/gmock",
+    "//testing/gtest",
+    "//ui/base",
+    "//ui/strings",
+  ]
+
+  if (is_mac) {
+    # Resolve paths owing to different test executable locations
+    ldflags = [
+      "-F",
+      rebase_path("external_binaries", root_build_dir),
+      "-rpath",
+      "@loader_path",
+      "-rpath",
+      "@executable_path/" + rebase_path("external_binaries", root_build_dir),
+    ]
+  }
+}
+
 template("dist_zip") {
  _runtime_deps_target = "${target_name}__deps"
  _runtime_deps_file =
@@ -1196,104 +1181,107 @@ template("dist_zip") {

  action(target_name) {
    script = "//electron/build/zip.py"
-    deps = [
-      ":$_runtime_deps_target",
-    ]
+    deps = [ ":$_runtime_deps_target" ]
    forward_variables_from(invoker,
                           [
                             "outputs",
                             "testonly",
                           ])
+    flatten = false
+    if (defined(invoker.flatten)) {
+      flatten = invoker.flatten
+    }
    args = rebase_path(outputs + [ _runtime_deps_file ], root_build_dir) + [
             target_cpu,
             target_os,
+             "$flatten",
           ]
  }
 }

 copy("electron_license") {
-  sources = [
-    "LICENSE",
-  ]
-  outputs = [
-    "$root_build_dir/{{source_file_part}}",
-  ]
+  sources = [ "LICENSE" ]
+  outputs = [ "$root_build_dir/{{source_file_part}}" ]
 }
 copy("chromium_licenses") {
-  deps = [
-    "//components/resources:about_credits",
-  ]
-  sources = [
-    "$root_gen_dir/components/resources/about_credits.html",
-  ]
-  outputs = [
-    "$root_build_dir/LICENSES.chromium.html",
-  ]
+  deps = [ "//components/resources:about_credits" ]
+  sources = [ "$root_gen_dir/components/resources/about_credits.html" ]
+  outputs = [ "$root_build_dir/LICENSES.chromium.html" ]
 }

 group("licenses") {
  data_deps = [
-    ":electron_license",
    ":chromium_licenses",
+    ":electron_license",
  ]
 }

 copy("electron_version") {
-  sources = [
-    "ELECTRON_VERSION",
-  ]
-  outputs = [
-    "$root_build_dir/version",
-  ]
+  sources = [ "ELECTRON_VERSION" ]
+  outputs = [ "$root_build_dir/version" ]
 }

 dist_zip("electron_dist_zip") {
  data_deps = [
    ":electron_app",
-    ":licenses",
    ":electron_version",
+    ":licenses",
  ]
  if (is_linux) {
    data_deps += [ "//sandbox/linux:chrome_sandbox" ]
  }
-  outputs = [
-    "$root_build_dir/dist.zip",
-  ]
+  outputs = [ "$root_build_dir/dist.zip" ]
 }

 dist_zip("electron_ffmpeg_zip") {
-  data_deps = [
-    "//third_party/ffmpeg",
-  ]
-  outputs = [
-    "$root_build_dir/ffmpeg.zip",
-  ]
+  data_deps = [ "//third_party/ffmpeg" ]
+  outputs = [ "$root_build_dir/ffmpeg.zip" ]
+}
+
+electron_chromedriver_deps = [
+  ":licenses",
+  "//chrome/test/chromedriver",
+  "//electron/buildflags",
+]
+
+group("electron_chromedriver") {
+  testonly = true
+  public_deps = electron_chromedriver_deps
 }

 dist_zip("electron_chromedriver_zip") {
  testonly = true
-  data_deps = [
-    "//chrome/test/chromedriver",
-    ":licenses",
-  ]
-  outputs = [
-    "$root_build_dir/chromedriver.zip",
-  ]
+  data_deps = electron_chromedriver_deps
+  outputs = [ "$root_build_dir/chromedriver.zip" ]
+}
+
+mksnapshot_deps = [
+  ":licenses",
+  "//tools/v8_context_snapshot:v8_context_snapshot_generator",
+  "//v8:mksnapshot($v8_snapshot_toolchain)",
+]
+
+group("electron_mksnapshot") {
+  public_deps = mksnapshot_deps
 }

 dist_zip("electron_mksnapshot_zip") {
-  data_deps = [
-    "//v8:mksnapshot($v8_snapshot_toolchain)",
-    "//tools/v8_context_snapshot:v8_context_snapshot_generator",
-    ":licenses",
-  ]
-  outputs = [
-    "$root_build_dir/mksnapshot.zip",
-  ]
+  data_deps = mksnapshot_deps
+  outputs = [ "$root_build_dir/mksnapshot.zip" ]
+}
+
+copy("hunspell_dictionaries") {
+  sources = hunspell_dictionaries + hunspell_licenses
+  outputs = [ "$target_gen_dir/electron_hunspell/{{source_file_part}}" ]
+}
+
+dist_zip("hunspell_dictionaries_zip") {
+  data_deps = [ ":hunspell_dictionaries" ]
+  flatten = true
+
+  outputs = [ "$root_build_dir/hunspell_dictionaries.zip" ]
 }

 group("electron") {
-  public_deps = [
-    ":electron_app",
-  ]
+  public_deps = [ ":electron_app" ]
 }
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -20,13 +20,11 @@ Issues are created [here](https://github.com/electron/electron/issues/new).
 * [Triaging a Bug Report](https://electronjs.org/docs/development/issues#triaging-a-bug-report)
 * [Resolving a Bug Report](https://electronjs.org/docs/development/issues#resolving-a-bug-report)

-### Issue Maintenance and Closure
-* If an issue is inactive for 45 days (no activity of any kind), it will be
-marked for closure with `stale`.
-* If after this label is applied, no further activity occurs in the next 7 days,
-the issue will be closed.
-  * If an issue has been closed and you still feel it's relevant, feel free to
-  ping a maintainer or add a comment!
+### Issue Closure
+
+Bug reports will be closed if the issue has been inactive and the latest affected version no longer receives support. At the moment, Electron maintains its three latest major versions, with a new major version being released every 12 weeks. (For more information on Electron's release cadence, see [this blog post](https://electronjs.org/blog/12-week-cadence).)
+
+_If an issue has been closed and you still feel it's relevant, feel free to ping a maintainer or add a comment!_

 ### Languages

--- a/14
+++ b/14
@@ -5,14 +5,16 @@ gclient_gn_args = [
  'checkout_android_native_support',
  'checkout_libaom',
  'checkout_nacl',
-  'checkout_oculus_sdk'
+  'checkout_oculus_sdk',
+  'checkout_openxr',
+  'checkout_google_benchmark'
 ]

 vars = {
  'chromium_version':
-    '62327c655093c821aa0fcfc6db53f5fd943e08c7',
+    '2102ff0fb03469ca5ff317a168e6ad99ca0f23f1',
  'node_version':
-    'v12.9.1',
+    'v12.14.1',
  'nan_version':
    '2ee313aaca52e2b478965ac50eb5082520380d1b',

@@ -60,12 +62,16 @@ vars = {
    True,
  'checkout_oculus_sdk':
    False,
+  'checkout_openxr':
+    False,
  'build_with_chromium':
    True,
  'checkout_android':
    False,
  'checkout_android_native_support':
    False,
+  'checkout_google_benchmark':
+    False,
 }

 deps = {
@@ -111,7 +117,7 @@ hooks = [
    'pattern': 'src/electron/script/update-external-binaries.py',
    'condition': 'download_external_binaries',
    'action': [
-      'python',
+      'python3',
      'src/electron/script/update-external-binaries.py',
    ],
  },
--- a/50
+++ b/50
@@ -1,50 +0,0 @@
-FROM ubuntu:18.04
-
-RUN groupadd --gid 1000 builduser \
-  && useradd --uid 1000 --gid builduser --shell /bin/bash --create-home builduser
-
-# Set up TEMP directory
-ENV TEMP=/tmp
-RUN chmod a+rwx /tmp
-
-# Install Linux packages
-ADD build/install-build-deps.sh /setup/install-build-deps.sh
-RUN echo ttf-mscorefonts-installer msttcorefonts/accepted-mscorefonts-eula select true | debconf-set-selections
-RUN dpkg --add-architecture i386
-RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y \
-    curl \
-    libnotify-bin \
-    locales \
-    lsb-release \
-    nano \
-    python-dbus \
-    python-pip \
-    python-setuptools \
-    sudo \
-    vim-nox \
-    wget \
-    g++-multilib \
-    libgl1:i386 \
-  && /setup/install-build-deps.sh --syms --no-prompt --no-chromeos-fonts --lib32 --arm \
-  && rm -rf /var/lib/apt/lists/*
-
-# Install Node.js
-RUN curl -sL https://deb.nodesource.com/setup_10.x | bash - \
-  && DEBIAN_FRONTEND=noninteractive apt-get install -y nodejs \
-  && rm -rf /var/lib/apt/lists/*
-
-# crcmod is required by gsutil, which is used for filling the gclient git cache
-RUN pip install -U crcmod
-
-# dbusmock is needed for Electron tests
-RUN pip install python-dbusmock
-
-RUN mkdir /tmp/workspace
-RUN chown builduser:builduser /tmp/workspace
-
-# Add xvfb init script
-ADD tools/xvfb-init.sh /etc/init.d/xvfb
-RUN chmod a+x /etc/init.d/xvfb
-
-USER builduser
-WORKDIR /home/builduser
--- a/Dockerfile.arm32v7
+++ b/Dockerfile.arm32v7
@@ -1,59 +0,0 @@
-FROM arm32v7/ubuntu:18.04
-
-RUN groupadd --gid 1000 builduser \
-  && useradd --uid 1000 --gid builduser --shell /bin/bash --create-home builduser
-
-# Set up TEMP directory
-ENV TEMP=/tmp
-RUN chmod a+rwx /tmp
-
-RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y \
- bison \
- build-essential \
- clang \
- curl \
- gperf \
- git \
- libasound2 \
- libasound2-dev \
- libcap-dev \
- libcups2-dev \
- libdbus-1-dev \
- libgnome-keyring-dev \
- libgtk2.0-0 \
- libgtk2.0-dev \
- libgtk-3-0 \
- libgtk-3-dev \
- libnotify-bin \
- libnss3 \
- libnss3-dev \
- libxss1 \
- libxtst-dev \
- libxtst6 \
- lsb-release \
- locales \
- nano \
- python-setuptools \
- python-pip \
- python-dbusmock \
- sudo \
- unzip \
- wget \
- xvfb \
-&& rm -rf /var/lib/apt/lists/*
-
-# Install Node.js
-RUN curl -sL https://deb.nodesource.com/setup_10.x | bash - \
-  && DEBIAN_FRONTEND=noninteractive apt-get install -y nodejs \
-  && rm -rf /var/lib/apt/lists/*
-
-# crcmod is required by gsutil, which is used for filling the gclient git cache
-RUN pip install -U crcmod
-
-ADD tools/xvfb-init.sh /etc/init.d/xvfb
-RUN chmod a+x /etc/init.d/xvfb
-
-RUN usermod -aG sudo builduser
-RUN echo 'builduser ALL=(ALL:ALL) NOPASSWD:ALL' >> /etc/sudoers
-
-WORKDIR /home/builduser
--- a/Dockerfile.arm64v8
+++ b/Dockerfile.arm64v8
@@ -1,65 +0,0 @@
-FROM arm64v8/ubuntu:18.04
-
-RUN groupadd --gid 1000 builduser \
-  && useradd --uid 1000 --gid builduser --shell /bin/bash --create-home builduser
-
-# Set up TEMP directory
-ENV TEMP=/tmp
-RUN chmod a+rwx /tmp
-
-RUN dpkg --add-architecture armhf
-
-RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y \
- bison \
- build-essential \
- clang \
- curl \
- gperf \
- git \
- libasound2 \
- libasound2-dev \
- libc6:armhf \
- libcap-dev \
- libcups2-dev \
- libdbus-1-dev \
- libgnome-keyring-dev \
- libgtk2.0-0 \
- libgtk2.0-dev \
- libgtk-3-0 \
- libgtk-3-dev \
- libnotify-bin \
- libnss3 \
- libnss3-dev \
- libstdc++6:armhf \
- libxss1 \
- libxtst-dev \
- libxtst6 \
- lsb-release \
- locales \
- nano \
- python-setuptools \
- python-pip \
- sudo \
- unzip \
- wget \
- xvfb \
-&& rm -rf /var/lib/apt/lists/*
-
-# Install Node.js
-RUN curl -sL https://deb.nodesource.com/setup_10.x | bash - \
-  && DEBIAN_FRONTEND=noninteractive apt-get install -y nodejs \
-  && rm -rf /var/lib/apt/lists/*
-
-# crcmod is required by gsutil, which is used for filling the gclient git cache
-RUN pip install -U crcmod
-
-# dbusmock is needed for Electron tests
-RUN pip install python-dbusmock
-
-ADD tools/xvfb-init.sh /etc/init.d/xvfb
-RUN chmod a+x /etc/init.d/xvfb
-
-RUN usermod -aG sudo builduser
-RUN echo 'builduser ALL=(ALL:ALL) NOPASSWD:ALL' >> /etc/sudoers
-
-WORKDIR /home/builduser
--- a/2
+++ b/2
@@ -1 +1 @@
-8.0.0-nightly.20190918
+9.0.0-beta.1
--- a/2
+++ b/2
@@ -1,4 +1,4 @@
-Copyright (c) 2013-2019 GitHub Inc.
+Copyright (c) 2013-2020 GitHub Inc.

 Permission is hereby granted, free of charge, to any person obtaining
 a copy of this software and associated documentation files (the
--- a/README.md
+++ b/README.md
@@ -58,13 +58,13 @@ npm start

 ## Resources for learning Electron

- [electronjs.org/docs](https://electronjs.org/docs) - all of Electron's documentation
+- [electronjs.org/docs](https://electronjs.org/docs) - All of Electron's documentation
 - [electron/fiddle](https://github.com/electron/fiddle) - A tool to build, run, and package small Electron experiments
- [electron/electron-quick-start](https://github.com/electron/electron-quick-start) - a very basic starter Electron app
- [electronjs.org/community#boilerplates](https://electronjs.org/community#boilerplates) - sample starter apps created by the community
- [electron/simple-samples](https://github.com/electron/simple-samples) - small applications with ideas for taking them further
- [electron/electron-api-demos](https://github.com/electron/electron-api-demos) - an Electron app that teaches you how to use Electron
- [hokein/electron-sample-apps](https://github.com/hokein/electron-sample-apps) - small demo apps for the various Electron APIs
+- [electron/electron-quick-start](https://github.com/electron/electron-quick-start) - A very basic starter Electron app
+- [electronjs.org/community#boilerplates](https://electronjs.org/community#boilerplates) - Sample starter apps created by the community
+- [electron/simple-samples](https://github.com/electron/simple-samples) - Small applications with ideas for taking them further
+- [electron/electron-api-demos](https://github.com/electron/electron-api-demos) - An Electron app that teaches you how to use Electron
+- [hokein/electron-sample-apps](https://github.com/hokein/electron-sample-apps) - Small demo apps for the various Electron APIs

 ## Programmatic usage

--- a/appveyor.yml
+++ b/appveyor.yml
@@ -1,5 +1,5 @@
 # The config expects the following environment variables to be set:
-#  - "GN_CONFIG" Build type. One of {'debug', 'testing', 'release'}.
+#  - "GN_CONFIG" Build type. One of {'testing', 'release'}.
 #  - "GN_EXTRA_ARGS" Additional gn arguments for a build config,
 #      e.g. 'target_cpu="x86"' to build for a 32bit platform.
 #      https://gn.googlesource.com/gn/+/master/docs/reference.md#target_cpu
@@ -29,7 +29,7 @@

 version: 1.0.{build}
 build_cloud: libcc-20
-image: vs2017-15.9-10.0.18362
+image: vs2019bt-16.4.0
 environment:
  GIT_CACHE_PATH: C:\Users\electron\libcc_cache
  ELECTRON_OUT_DIR: Default
@@ -50,6 +50,12 @@ build_script:
  - ps: >-
      if(($env:APPVEYOR_PULL_REQUEST_HEAD_REPO_NAME -split "/")[0] -eq ($env:APPVEYOR_REPO_NAME -split "/")[0]) {
        Write-warning "Skipping PR build for branch"; Exit-AppveyorBuild
+      } else {
+        node script/yarn.js install --frozen-lockfile
+
+        if ($(node script/doc-only-change.js --prNumber=$env:APPVEYOR_PULL_REQUEST_NUMBER --prBranch=$env:APPVEYOR_REPO_BRANCH;$LASTEXITCODE -eq 0)) {
+          Write-warning "Skipping build for doc only change"; Exit-AppveyorBuild
+        }
      }
  - echo "Building $env:GN_CONFIG build"
  - git config --global core.longpaths true
@@ -70,28 +76,81 @@ build_script:
      --unmanaged
      %GCLIENT_EXTRA_ARGS%
      "https://github.com/electron/electron"
-  - gclient sync --with_branch_heads --with_tags --reset
+  - ps: >-
+      if ($env:GN_CONFIG -eq 'release') {
+        $env:RUN_GCLIENT_SYNC="true"
+      } else {
+        cd src\electron
+        node script\generate-deps-hash.js
+        $depshash = Get-Content .\.depshash -Raw 
+        $zipfile = "Z:\$depshash.7z"
+        cd ..\..
+        if (Test-Path -Path $zipfile) {
+          # file exists, unzip and then gclient sync
+          7z x -y $zipfile -mmt=30 -aoa
+          if (-not (Test-Path -Path "src\buildtools")) {
+            # the zip file must be corrupt - resync
+            $env:RUN_GCLIENT_SYNC="true"
+            if ($env:TARGET_ARCH -ne 'ia32') {
+              # only save on x64/woa to avoid contention saving
+              $env:SAVE_GCLIENT_SRC="true"
+            }
+          } else {
+            # update external binaries
+            python src/electron/script/update-external-binaries.py
+          }
+        } else {    
+          # file does not exist, gclient sync, then zip
+          $env:RUN_GCLIENT_SYNC="true"
+          if ($env:TARGET_ARCH -ne 'ia32') {
+            # only save on x64/woa to avoid contention saving
+            $env:SAVE_GCLIENT_SRC="true"
+          }
+        }
+      }
+  - if "%RUN_GCLIENT_SYNC%"=="true" ( gclient sync --with_branch_heads --with_tags --ignore_locks)
+  - ps: >-
+      if ($env:SAVE_GCLIENT_SRC -eq 'true') {
+        # archive current source for future use 
+        # only run on x64/woa to avoid contention saving
+        if ($(7z a $zipfile src -xr!android_webview -xr!electron -xr'!*\.git' -xr!third_party\WebKit\LayoutTests! -xr!third_party\blink\web_tests -xr!third_party\blink\perf_tests -slp -t7z -mmt=30;$LASTEXITCODE -ne 0)) {
+          Write-warning "Could not save source to shared drive; continuing anyway"
+        }
+      }
+  - ps: >-
+      if (Test-Path 'env:RAW_GOMA_AUTH') {
+        $env:GOMA_OAUTH2_CONFIG_FILE = "$pwd\.goma_oauth2_config"
+        $env:RAW_GOMA_AUTH | Set-Content $env:GOMA_OAUTH2_CONFIG_FILE
+        .\src\electron\script\start-goma.ps1 -gomaDir "$pwd\src\electron\external_binaries\goma"
+      }
  - cd src
-  - ps: $env:BUILD_CONFIG_PATH="//electron/build/args/%GN_CONFIG%.gn"
-  - gn gen out/Default "--args=import(\"%BUILD_CONFIG_PATH%\") %GN_EXTRA_ARGS%"
+  - set BUILD_CONFIG_PATH=//electron/build/args/%GN_CONFIG%.gn 
+  - if DEFINED RAW_GOMA_AUTH (gn gen out/Default "--args=import(\"%BUILD_CONFIG_PATH%\") import(\"//electron/build/args/goma.gn\") %GN_EXTRA_ARGS% ") else (gn gen out/Default "--args=import(\"%BUILD_CONFIG_PATH%\") %GN_EXTRA_ARGS% cc_wrapper=\"%SCCACHE_PATH%\"")
  - gn check out/Default //electron:electron_lib
  - gn check out/Default //electron:electron_app
  - gn check out/Default //electron:manifests
  - gn check out/Default //electron/shell/common/api:mojo
-  - ninja -C out/Default electron:electron_app
-  - if "%GN_CONFIG%"=="testing" ( python C:\Users\electron\depot_tools\post_build_ninja_summary.py -C out\Default )  
+  - if DEFINED RAW_GOMA_AUTH (ninja -j 300 -C out/Default electron:electron_app) else (ninja -C out/Default electron:electron_app)
+  - if "%GN_CONFIG%"=="testing" ( python C:\depot_tools\post_build_ninja_summary.py -C out\Default )
  - gn gen out/ffmpeg "--args=import(\"//electron/build/args/ffmpeg.gn\") %GN_EXTRA_ARGS%"
  - ninja -C out/ffmpeg electron:electron_ffmpeg_zip
  - ninja -C out/Default electron:electron_dist_zip
+  - ninja -C out/Default shell_browser_ui_unittests
  - ninja -C out/Default electron:electron_mksnapshot_zip
+  - ninja -C out/Default electron:hunspell_dictionaries_zip
  - ninja -C out/Default electron:electron_chromedriver_zip
  - ninja -C out/Default third_party/electron_node:headers
+  - if DEFINED RAW_GOMA_AUTH (python electron\external_binaries\goma\goma_ctl.py stat)
+  - python electron/build/profile_toolchain.py --output-json=out/Default/windows_toolchain_profile.json
+  - appveyor PushArtifact out/Default/windows_toolchain_profile.json
  - appveyor PushArtifact out/Default/dist.zip
+  - appveyor PushArtifact out/Default/shell_browser_ui_unittests.exe
  - appveyor PushArtifact out/Default/chromedriver.zip
  - appveyor PushArtifact out/ffmpeg/ffmpeg.zip
  - 7z a node_headers.zip out\Default\gen\node_headers
  - appveyor PushArtifact node_headers.zip
  - appveyor PushArtifact out/Default/mksnapshot.zip
+  - appveyor PushArtifact out/Default/hunspell_dictionaries.zip
  - appveyor PushArtifact out/Default/electron.lib
  - ps: >-
      if ($env:GN_CONFIG -eq 'release') {
@@ -102,7 +161,12 @@ build_script:
  - ps: >-
      if ($env:GN_CONFIG -eq 'release') {
        python electron\script\zip-symbols.py
-        appveyor PushArtifact out/Default/symbols.zip
+        appveyor-retry appveyor PushArtifact out/Default/symbols.zip
+      } else {
+        # It's useful to have pdb files when debugging testing builds that are
+        # built on CI.
+        7z a pdb.zip out\Default\*.pdb
+        appveyor-retry appveyor PushArtifact pdb.zip
      }
  - python electron/script/zip_manifests/check-zip-manifest.py out/Default/dist.zip electron/script/zip_manifests/dist_zip.win.%TARGET_ARCH%.manifest
 test_script:
@@ -120,12 +184,15 @@ test_script:
        echo "Skipping tests for $env:GN_CONFIG build"
      }
  - cd electron
-  - if "%RUN_TESTS%"=="true" ( echo Running test suite & node script/yarn test -- --ci --enable-logging)
+  - if "%RUN_TESTS%"=="true" ( echo Running test suite & node script/yarn test -- --enable-logging)
  - cd ..
  - if "%RUN_TESTS%"=="true" ( echo Verifying non proprietary ffmpeg & python electron\script\verify-ffmpeg.py --build-dir out\Default --source-root %cd% --ffmpeg-path out\ffmpeg )
-  - echo "About to verify mksnapshot"
+  - echo "About to verify mksnapshot"  
+  - if "%RUN_TESTS%"=="true" ( gn desc out\Default v8:run_mksnapshot_default args > out\Default\mksnapshot_args )
  - if "%RUN_TESTS%"=="true" ( echo Verifying mksnapshot & python electron\script\verify-mksnapshot.py --build-dir out\Default --source-root %cd% )
  - echo "Done verifying mksnapshot"
+  - if "%RUN_TESTS%"=="true" ( echo Verifying chromedriver & python electron\script\verify-chromedriver.py --build-dir out\Default --source-root %cd% )
+  - echo "Done verifying chromedriver"
 deploy_script:
  - cd electron
  - ps: >-
--- a/azure-pipelines-woa.yml
+++ b/azure-pipelines-woa.yml
@@ -18,6 +18,14 @@ steps:
  env:
    APPVEYOR_TOKEN: $(APPVEYOR_TOKEN)

+- powershell: |
+    $localArtifactPath = "$pwd\src\out\Default\shell_browser_ui_unittests.exe"
+    $serverArtifactPath = "$env:APPVEYOR_URL/buildjobs/$env:APPVEYOR_JOB_ID/artifacts/shell_browser_ui_unittests.exe"
+    Invoke-RestMethod -Method Get -Uri $serverArtifactPath -OutFile $localArtifactPath -Headers @{ "Authorization" = "Bearer $env:APPVEYOR_TOKEN" }
+  displayName: 'Download and extract native test executables for test'
+  env:
+    APPVEYOR_TOKEN: $(APPVEYOR_TOKEN)
+
 - powershell: |
    $localArtifactPath = "$pwd\ffmpeg.zip"
    $serverArtifactPath = "$env:APPVEYOR_URL/buildjobs/$env:APPVEYOR_JOB_ID/artifacts/ffmpeg.zip"
@@ -55,7 +63,7 @@ steps:
    set npm_config_nodedir=%cd%\out\Default\gen\node_headers
    set npm_config_arch=arm64
    cd electron
-    node script/yarn test -- --ci --enable-logging --verbose
+    node script/yarn test -- --enable-logging --verbose
  displayName: 'Run Electron tests'
  env:
    ELECTRON_OUT_DIR: Default
@@ -77,8 +85,8 @@ steps:
    python electron\script\verify-ffmpeg.py --build-dir out\Default --source-root %cd% --ffmpeg-path out\ffmpeg
  displayName: 'Verify ffmpeg'

- script: |
-    taskkill /F /IM electron.exe
-    taskkill /F /IM MicrosoftEdge.exe
+- powershell: |
+    Get-Process | Where Name –Like "electron*" | Stop-Process
+    Get-Process | Where Name –Like "MicrosoftEdge*" | Stop-Process
  displayName: 'Kill processes left running from last test run'
-  condition: always()
+  condition: always()
--- a/build/args/all.gn
+++ b/build/args/all.gn
@@ -1,5 +1,4 @@
 is_electron_build = true
-use_jumbo_build = true
 root_extra_deps = [ "//electron" ]

 # Registry of NMVs --> https://github.com/nodejs/node/blob/master/doc/abi_version_registry.json
@@ -18,9 +17,11 @@ ffmpeg_branding = "Chrome"

 enable_basic_printing = true
 angle_enable_vulkan_validation_layers = false
+dawn_enable_vulkan_validation_layers = false

 is_cfi = false

-# TODO: Remove this and update CI to contain 10.14 SDK once
-# crbug.com/986701 is fixed.
-mac_sdk_min = "10.13"
+# TODO: disabled due to crashes. re-enable.
+enable_osr = false
+
+enable_electron_extensions = true
--- a/build/args/debug.gn
+++ b/build/args/debug.gn
@@ -1,10 +0,0 @@
-import("all.gn")
-is_debug = true
-is_component_build = true
-
-# This may be guarded behind is_chrome_branded alongside
-# proprietary_codecs https://webrtc-review.googlesource.com/c/src/+/36321,
-# explicitly override here to build OpenH264 encoder/FFmpeg decoder.
-# The initialization of the decoder depends on whether ffmpeg has
-# been built with H.264 support.
-rtc_use_h264 = proprietary_codecs
--- a/build/args/goma.gn
+++ b/build/args/goma.gn
@@ -0,0 +1,2 @@
+goma_dir = rebase_path("//electron/external_binaries/goma")
+use_goma = true
--- a/build/args/native_tests.gn
+++ b/build/args/native_tests.gn
@@ -5,4 +5,3 @@ is_debug = false
 is_component_build = false
 is_component_ffmpeg = false
 symbol_level = 1
-use_jumbo_build = true
--- a/build/extract_symbols.gni
+++ b/build/extract_symbols.gni
@@ -34,9 +34,7 @@ template("extract_symbols") {
      dump_syms_binary,
    ]
    stamp_file = "${target_gen_dir}/${target_name}.stamp"
-    outputs = [
-      stamp_file,
-    ]
+    outputs = [ stamp_file ]
    args = [
      "./" + rebase_path(dump_syms_binary, root_build_dir),
      rebase_path(invoker.binary, root_build_dir),
--- a/build/npm.gni
+++ b/build/npm.gni
@@ -10,9 +10,7 @@ template("npm_action") {
    ]
    script = "//electron/build/npm-run.py"

-    outputs = [
-      "$target_gen_dir/npm_pre_stamps/" + target_name + ".stamp",
-    ]
+    outputs = [ "$target_gen_dir/npm_pre_stamps/" + target_name + ".stamp" ]

    args = [
      "--silent",
--- a/build/profile_toolchain.py
+++ b/build/profile_toolchain.py
@@ -0,0 +1,98 @@
+from __future__ import with_statement
+import contextlib
+import sys
+import os
+import optparse
+import json
+
+sys.path.append("%s/../../build" % os.path.dirname(os.path.realpath(__file__)))
+
+import find_depot_tools
+from vs_toolchain import \
+    SetEnvironmentAndGetRuntimeDllDirs, \
+    SetEnvironmentAndGetSDKDir, \
+    GetVisualStudioVersion, \
+    NormalizePath
+
+sys.path.append("%s/win_toolchain" % find_depot_tools.add_depot_tools_to_path())
+
+from get_toolchain_if_necessary import CalculateHash
+
+
+@contextlib.contextmanager
+def cwd(dir):
+    curdir = os.getcwd()
+    try:
+        os.chdir(dir)
+        yield
+    finally:
+        os.chdir(curdir)
+
+
+def calculate_hash(root):
+    with cwd(root):
+        return CalculateHash('.', None)
+
+def windows_installed_software():
+    import win32com.client
+    strComputer = "."
+    objWMIService = win32com.client.Dispatch("WbemScripting.SWbemLocator")
+    objSWbemServices = objWMIService.ConnectServer(strComputer, "root\cimv2")
+    colItems = objSWbemServices.ExecQuery("Select * from Win32_Product")
+    items = []
+
+    for objItem in colItems:
+        item = {}
+        if objItem.Caption:
+            item['caption'] = objItem.Caption
+        if objItem.Caption:
+            item['description'] = objItem.Description
+        if objItem.InstallDate:
+            item['install_date'] = objItem.InstallDate
+        if objItem.InstallDate2:
+            item['install_date_2'] = objItem.InstallDate2
+        if objItem.InstallLocation:
+            item['install_location'] = objItem.InstallLocation
+        if objItem.Name:
+            item['name'] = objItem.Name
+        if objItem.SKUNumber:
+            item['sku_number'] = objItem.SKUNumber
+        if objItem.Vendor:
+            item['vendor'] = objItem.Vendor
+        if objItem.Version:
+            item['version'] = objItem.Version
+        items.append(item)
+
+    return items
+
+
+def windows_profile():
+    runtime_dll_dirs = SetEnvironmentAndGetRuntimeDllDirs()
+    win_sdk_dir = SetEnvironmentAndGetSDKDir()
+    path = NormalizePath(os.environ['GYP_MSVS_OVERRIDE_PATH'])
+
+    return {
+        'pwd': os.getcwd(), # since current windows executable are symbols path dependant, profile the current directory too
+        'installed_software': windows_installed_software(),
+        'sdks': [
+            {'name': 'vs', 'path': path, 'hash': calculate_hash(path)},
+            {'name': 'wsdk', 'path': win_sdk_dir, 'hash': calculate_hash(win_sdk_dir)}
+        ],
+        'runtime_lib_dirs': runtime_dll_dirs,
+    }
+
+
+def main(options):
+    if sys.platform == 'win32':
+        with open(options.output_json, 'wb') as f:
+            json.dump(windows_profile(), f)
+    else:
+        raise OSError("Unsupported OS")
+
+
+if __name__ == '__main__':
+  parser = optparse.OptionParser()
+  parser.add_option('--output-json', metavar='FILE', default='profile.json',
+                    help='write information about toolchain to FILE')
+  options, args = parser.parse_args()
+  sys.exit(main(options))
--- a/build/rules.gni
+++ b/build/rules.gni
@@ -0,0 +1,94 @@
+import("//build/config/mac/mac_sdk.gni")
+
+# Template to compile .xib and .storyboard files.
+# (copied from src/build/config/ios/rules.gni)
+#
+# Arguments
+#
+#     sources:
+#         list of string, sources to compile
+#
+#     ibtool_flags:
+#         (optional) list of string, additional flags to pass to the ibtool
+template("compile_ib_files") {
+  action_foreach(target_name) {
+    forward_variables_from(invoker,
+                           [
+                             "testonly",
+                             "visibility",
+                           ])
+    assert(defined(invoker.sources),
+           "sources must be specified for $target_name")
+    assert(defined(invoker.output_extension),
+           "output_extension must be specified for $target_name")
+
+    ibtool_flags = []
+    if (defined(invoker.ibtool_flags)) {
+      ibtool_flags = invoker.ibtool_flags
+    }
+
+    _output_extension = invoker.output_extension
+
+    script = "//build/config/ios/compile_ib_files.py"
+    sources = invoker.sources
+    outputs = [
+      "$target_gen_dir/$target_name/{{source_name_part}}.$_output_extension",
+    ]
+    args = [
+      "--input",
+      "{{source}}",
+      "--output",
+      rebase_path(
+          "$target_gen_dir/$target_name/{{source_name_part}}.$_output_extension",
+          root_build_dir),
+    ]
+    args += ibtool_flags
+  }
+}
+
+# Template is copied here from Chromium but was removed in
+# https://chromium-review.googlesource.com/c/chromium/src/+/1637981
+# Template to compile and package Mac XIB files as bundle data.
+# Arguments
+#     sources:
+#         list of string, sources to comiple
+#     output_path:
+#         (optional) string, the path to use for the outputs list in the
+#         bundle_data step. If unspecified, defaults to bundle_resources_dir.
+template("mac_xib_bundle_data") {
+  _target_name = target_name
+  _compile_target_name = _target_name + "_compile_ibtool"
+
+  compile_ib_files(_compile_target_name) {
+    forward_variables_from(invoker, [ "testonly" ])
+    visibility = [ ":$_target_name" ]
+    sources = invoker.sources
+    output_extension = "nib"
+    ibtool_flags = [
+      "--minimum-deployment-target",
+      mac_deployment_target,
+
+      # TODO(rsesek): Enable this once all the bots are on Xcode 7+.
+      # "--target-device",
+      # "mac",
+    ]
+  }
+
+  bundle_data(_target_name) {
+    forward_variables_from(invoker,
+                           [
+                             "testonly",
+                             "visibility",
+                           ])
+
+    public_deps = [ ":$_compile_target_name" ]
+    sources = get_target_outputs(":$_compile_target_name")
+
+    _output_path = "{{bundle_resources_dir}}"
+    if (defined(invoker.output_path)) {
+      _output_path = invoker.output_path
+    }
+
+    outputs = [ "$_output_path/{{source_file_part}}" ]
+  }
+}
--- a/build/templated_file.gni
+++ b/build/templated_file.gni
@@ -15,12 +15,8 @@ template("templated_file") {
                             "inputs",
                             "outputs",
                           ])
-    inputs = [
-      invoker.template,
-    ]
-    outputs = [
-      invoker.output,
-    ]
+    inputs = [ invoker.template ]
+    outputs = [ invoker.output ]
    script = "//electron/build/generate-template.py"
    args = [
      rebase_path(invoker.template),
--- a/build/webpack/webpack.config.base.js
+++ b/build/webpack/webpack.config.base.js
@@ -74,7 +74,10 @@ module.exports = ({
          global: ['@electron/internal/renderer/webpack-provider', '_global'],
          Buffer: ['@electron/internal/renderer/webpack-provider', 'Buffer'],
        })
-      ] : [])
+      ] : []),
+      new webpack.ProvidePlugin({
+        Promise: ['@electron/internal/common/webpack-globals-provider', 'Promise'],
+      }),
    ]
  })
-}
+}
--- a/build/webpack/webpack.gni
+++ b/build/webpack/webpack.gni
@@ -27,8 +27,6 @@ template("webpack_build") {
      rebase_path(invoker.out_file),
    ]

-    outputs = [
-      invoker.out_file,
-    ]
+    outputs = [ invoker.out_file ]
  }
 }
--- a/build/zip.py
+++ b/build/zip.py
@@ -9,6 +9,7 @@ EXTENSIONS_TO_SKIP = [
  '.pdb',
  '.mojom.js',
  '.mojom-lite.js',
+  '.info'
 ]

 PATHS_TO_SKIP = [
@@ -16,6 +17,10 @@ PATHS_TO_SKIP = [
  './libVkICD_mock_', #Skipping because these are outputs that we don't need
  './VkICD_mock_', #Skipping because these are outputs that we don't need

+  # Skipping because its an output of create_bundle from //build/config/mac/rules.gni
+  # that we don't need
+  'Electron.dSYM',
+
  # //chrome/browser:resources depends on this via
  # //chrome/browser/resources/ssl/ssl_error_assistant, but we don't need to
  # ship it.
@@ -46,19 +51,19 @@ def execute(argv):
    raise e

 def main(argv):
-  dist_zip, runtime_deps, target_cpu, target_os = argv
+  dist_zip, runtime_deps, target_cpu, target_os, flatten_val = argv
+  should_flatten = flatten_val == "true"
  dist_files = set()
  with open(runtime_deps) as f:
    for dep in f.readlines():
      dep = dep.strip()
-      dist_files.add(dep)
-  if sys.platform == 'darwin':
+      if not skip_path(dep, dist_zip, target_cpu):
+        dist_files.add(dep)
+  if sys.platform == 'darwin' and not should_flatten:
    execute(['zip', '-r', '-y', dist_zip] + list(dist_files))
  else:
    with zipfile.ZipFile(dist_zip, 'w', zipfile.ZIP_DEFLATED, allowZip64=True) as z:
      for dep in dist_files:
-        if skip_path(dep, dist_zip, target_cpu):
-          continue
        if os.path.isdir(dep):
          for root, dirs, files in os.walk(dep):
            for file in files:
@@ -67,7 +72,7 @@ def main(argv):
          basename = os.path.basename(dep)
          dirname = os.path.dirname(dep)
          arcname = os.path.join(dirname, 'chrome-sandbox') if basename == 'chrome_sandbox' else dep
-          z.write(dep, arcname)
+          z.write(dep, os.path.basename(arcname) if should_flatten else arcname)

 if __name__ == '__main__':
  sys.exit(main(sys.argv[1:]))
--- a/buildflags/BUILD.gn
+++ b/buildflags/BUILD.gn
@@ -12,12 +12,14 @@ buildflag_header("buildflags") {
    "ENABLE_DESKTOP_CAPTURER=$enable_desktop_capturer",
    "ENABLE_RUN_AS_NODE=$enable_run_as_node",
    "ENABLE_OSR=$enable_osr",
+    "ENABLE_REMOTE_MODULE=$enable_remote_module",
    "ENABLE_VIEW_API=$enable_view_api",
    "ENABLE_PEPPER_FLASH=$enable_pepper_flash",
    "ENABLE_PDF_VIEWER=$enable_pdf_viewer",
    "ENABLE_TTS=$enable_tts",
    "ENABLE_COLOR_CHOOSER=$enable_color_chooser",
    "ENABLE_ELECTRON_EXTENSIONS=$enable_electron_extensions",
+    "ENABLE_BUILTIN_SPELLCHECKER=$enable_builtin_spellchecker",
    "ENABLE_PICTURE_IN_PICTURE=$enable_picture_in_picture",
    "OVERRIDE_LOCATION_PROVIDER=$enable_fake_location_provider",
  ]
--- a/buildflags/buildflags.gni
+++ b/buildflags/buildflags.gni
@@ -10,6 +10,8 @@ declare_args() {

  enable_osr = true

+  enable_remote_module = true
+
  enable_view_api = false

  enable_pdf_viewer = false
@@ -31,4 +33,7 @@ declare_args() {

  # Enable Chrome extensions support.
  enable_electron_extensions = false
+
+  # Enable Spellchecker support
+  enable_builtin_spellchecker = true
 }
--- a/chromium_src/BUILD.gn
+++ b/chromium_src/BUILD.gn
@@ -3,6 +3,7 @@
 # found in the LICENSE file.

 import("//build/config/ui.gni")
+import("//components/spellcheck/spellcheck_build_features.gni")
 import("//electron/buildflags/buildflags.gni")
 import("//printing/buildflags/buildflags.gni")
 import("//third_party/widevine/cdm/widevine.gni")
@@ -31,6 +32,8 @@ static_library("chrome") {
    "//chrome/browser/icon_loader_win.cc",
    "//chrome/browser/icon_manager.cc",
    "//chrome/browser/icon_manager.h",
+    "//chrome/browser/media/webrtc/system_media_capture_permissions_mac.h",
+    "//chrome/browser/media/webrtc/system_media_capture_permissions_mac.mm",
    "//chrome/browser/net/chrome_mojo_proxy_resolver_factory.cc",
    "//chrome/browser/net/chrome_mojo_proxy_resolver_factory.h",
    "//chrome/browser/net/proxy_config_monitor.cc",
@@ -39,14 +42,15 @@ static_library("chrome") {
    "//chrome/browser/net/proxy_service_factory.h",
    "//chrome/browser/predictors/preconnect_manager.cc",
    "//chrome/browser/predictors/preconnect_manager.h",
+    "//chrome/browser/predictors/predictors_features.cc",
+    "//chrome/browser/predictors/predictors_features.h",
    "//chrome/browser/predictors/proxy_lookup_client_impl.cc",
    "//chrome/browser/predictors/proxy_lookup_client_impl.h",
    "//chrome/browser/predictors/resolve_host_client_impl.cc",
    "//chrome/browser/predictors/resolve_host_client_impl.h",
-    "//chrome/browser/printing/printing_service.cc",
-    "//chrome/browser/printing/printing_service.h",
    "//chrome/browser/ssl/security_state_tab_helper.cc",
    "//chrome/browser/ssl/security_state_tab_helper.h",
+    "//chrome/browser/ssl/tls_deprecation_config.cc",
    "//chrome/browser/ui/autofill/popup_view_common.cc",
    "//chrome/browser/ui/autofill/popup_view_common.h",
    "//chrome/browser/win/chrome_process_finder.cc",
@@ -64,6 +68,7 @@ static_library("chrome") {
  ]
  deps = [
    "//chrome/browser:resource_prefetch_predictor_proto",
+    "//chrome/browser/ssl:proto",
    "//components/feature_engagement:buildflags",
  ]

@@ -72,6 +77,14 @@ static_library("chrome") {
    sources += [
      "//chrome/browser/extensions/global_shortcut_listener_x11.cc",
      "//chrome/browser/extensions/global_shortcut_listener_x11.h",
+      "//chrome/browser/ui/views/status_icons/concat_menu_model.cc",
+      "//chrome/browser/ui/views/status_icons/concat_menu_model.h",
+      "//chrome/browser/ui/views/status_icons/status_icon_linux_dbus.cc",
+      "//chrome/browser/ui/views/status_icons/status_icon_linux_dbus.h",
+    ]
+    public_deps += [
+      "//components/dbus/menu",
+      "//components/dbus/thread_linux",
    ]
  }

@@ -135,10 +148,6 @@ static_library("chrome") {
    sources += [
      "//chrome/browser/speech/tts_controller_delegate_impl.cc",
      "//chrome/browser/speech/tts_controller_delegate_impl.h",
-      "//chrome/browser/speech/tts_message_filter.cc",
-      "//chrome/browser/speech/tts_message_filter.h",
-      "//chrome/renderer/tts_dispatcher.cc",
-      "//chrome/renderer/tts_dispatcher.h",
    ]
  }

@@ -168,15 +177,17 @@ static_library("chrome") {
      "//chrome/browser/printing/printer_query.h",
      "//chrome/browser/printing/printing_message_filter.cc",
      "//chrome/browser/printing/printing_message_filter.h",
+      "//chrome/browser/printing/printing_service.cc",
+      "//chrome/browser/printing/printing_service.h",
    ]

    public_deps += [
      "//chrome/services/printing:lib",
      "//components/printing/browser",
      "//components/printing/renderer",
-      "//components/services/pdf_compositor",
-      "//components/services/pdf_compositor/public/cpp",
-      "//components/services/pdf_compositor/public/mojom",
+      "//components/services/print_compositor",
+      "//components/services/print_compositor/public/cpp",
+      "//components/services/print_compositor/public/mojom",
    ]

    deps += [
@@ -202,8 +213,6 @@ static_library("chrome") {
      "//chrome/browser/ui/views/overlay/back_to_tab_image_button.h",
      "//chrome/browser/ui/views/overlay/close_image_button.cc",
      "//chrome/browser/ui/views/overlay/close_image_button.h",
-      "//chrome/browser/ui/views/overlay/mute_image_button.cc",
-      "//chrome/browser/ui/views/overlay/mute_image_button.h",
      "//chrome/browser/ui/views/overlay/overlay_window_views.cc",
      "//chrome/browser/ui/views/overlay/overlay_window_views.h",
      "//chrome/browser/ui/views/overlay/playback_image_button.cc",
@@ -221,4 +230,142 @@ static_library("chrome") {
      "//components/vector_icons:vector_icons",
    ]
  }
+
+  if (enable_electron_extensions) {
+    sources += [
+      "//chrome/renderer/extensions/extension_hooks_delegate.cc",
+      "//chrome/renderer/extensions/extension_hooks_delegate.h",
+      "//chrome/renderer/extensions/tabs_hooks_delegate.cc",
+      "//chrome/renderer/extensions/tabs_hooks_delegate.h",
+    ]
+  }
+}
+
+source_set("plugins") {
+  sources = []
+  deps = []
+  libs = []
+
+  # browser side
+  sources += [
+    "//chrome/browser/renderer_host/pepper/chrome_browser_pepper_host_factory.cc",
+    "//chrome/browser/renderer_host/pepper/chrome_browser_pepper_host_factory.h",
+    "//chrome/browser/renderer_host/pepper/pepper_broker_message_filter.cc",
+    "//chrome/browser/renderer_host/pepper/pepper_broker_message_filter.h",
+    "//chrome/browser/renderer_host/pepper/pepper_isolated_file_system_message_filter.cc",
+    "//chrome/browser/renderer_host/pepper/pepper_isolated_file_system_message_filter.h",
+  ]
+  deps += [
+    "//media:media_buildflags",
+    "//ppapi/buildflags",
+    "//ppapi/proxy:ipc",
+    "//services/device/public/mojom",
+  ]
+  if (enable_pepper_flash) {
+    sources += [
+      "//chrome/browser/renderer_host/pepper/pepper_flash_browser_host.cc",
+      "//chrome/browser/renderer_host/pepper/pepper_flash_browser_host.h",
+      "//chrome/browser/renderer_host/pepper/pepper_flash_clipboard_message_filter.cc",
+      "//chrome/browser/renderer_host/pepper/pepper_flash_clipboard_message_filter.h",
+      "//chrome/browser/renderer_host/pepper/pepper_flash_drm_host.cc",
+      "//chrome/browser/renderer_host/pepper/pepper_flash_drm_host.h",
+    ]
+    if (is_mac) {
+      sources += [
+        "//chrome/browser/renderer_host/pepper/monitor_finder_mac.h",
+        "//chrome/browser/renderer_host/pepper/monitor_finder_mac.mm",
+      ]
+      libs += [ "CoreGraphics.framework" ]
+    }
+    if (is_linux) {
+      deps += [ "//components/services/font/public/cpp" ]
+    }
+  }
+
+  # renderer side
+  sources += [
+    "//chrome/renderer/pepper/chrome_renderer_pepper_host_factory.cc",
+    "//chrome/renderer/pepper/chrome_renderer_pepper_host_factory.h",
+    "//chrome/renderer/pepper/pepper_shared_memory_message_filter.cc",
+    "//chrome/renderer/pepper/pepper_shared_memory_message_filter.h",
+  ]
+  if (enable_pepper_flash) {
+    sources += [
+      "//chrome/renderer/pepper/pepper_flash_drm_renderer_host.cc",
+      "//chrome/renderer/pepper/pepper_flash_drm_renderer_host.h",
+      "//chrome/renderer/pepper/pepper_flash_font_file_host.cc",
+      "//chrome/renderer/pepper/pepper_flash_font_file_host.h",
+      "//chrome/renderer/pepper/pepper_flash_fullscreen_host.cc",
+      "//chrome/renderer/pepper/pepper_flash_fullscreen_host.h",
+      "//chrome/renderer/pepper/pepper_flash_menu_host.cc",
+      "//chrome/renderer/pepper/pepper_flash_menu_host.h",
+      "//chrome/renderer/pepper/pepper_flash_renderer_host.cc",
+      "//chrome/renderer/pepper/pepper_flash_renderer_host.h",
+    ]
+  }
+  deps += [
+    "//components/strings",
+    "//media:media_buildflags",
+    "//ppapi/host",
+    "//ppapi/proxy",
+    "//ppapi/proxy:ipc",
+    "//ppapi/shared_impl",
+    "//skia",
+  ]
+}
+
+# This source set is just so we don't have to depend on all of //chrome/browser
+# You may have to add new files here during the upgrade if //chrome/browser/spellchecker
+# gets more files
+source_set("chrome_spellchecker") {
+  sources = []
+  deps = []
+  libs = []
+
+  if (enable_builtin_spellchecker) {
+    sources += [
+      "//chrome/browser/spellchecker/spell_check_host_chrome_impl.cc",
+      "//chrome/browser/spellchecker/spell_check_host_chrome_impl.h",
+      "//chrome/browser/spellchecker/spellcheck_custom_dictionary.cc",
+      "//chrome/browser/spellchecker/spellcheck_custom_dictionary.h",
+      "//chrome/browser/spellchecker/spellcheck_factory.cc",
+      "//chrome/browser/spellchecker/spellcheck_factory.h",
+      "//chrome/browser/spellchecker/spellcheck_hunspell_dictionary.cc",
+      "//chrome/browser/spellchecker/spellcheck_hunspell_dictionary.h",
+      "//chrome/browser/spellchecker/spellcheck_language_blacklist_policy_handler.cc",
+      "//chrome/browser/spellchecker/spellcheck_language_blacklist_policy_handler.h",
+      "//chrome/browser/spellchecker/spellcheck_language_policy_handler.cc",
+      "//chrome/browser/spellchecker/spellcheck_language_policy_handler.h",
+      "//chrome/browser/spellchecker/spellcheck_service.cc",
+      "//chrome/browser/spellchecker/spellcheck_service.h",
+      "//chrome/common/pref_names.h",
+    ]
+
+    if (has_spellcheck_panel) {
+      sources += [
+        "//chrome/browser/spellchecker/spell_check_panel_host_impl.cc",
+        "//chrome/browser/spellchecker/spell_check_panel_host_impl.h",
+      ]
+    }
+
+    if (use_browser_spellchecker) {
+      sources += [
+        "//chrome/browser/spellchecker/spelling_request.cc",
+        "//chrome/browser/spellchecker/spelling_request.h",
+      ]
+    }
+
+    deps += [
+      "//base:base_static",
+      "//components/language/core/browser",
+      "//components/spellcheck:buildflags",
+      "//components/sync",
+    ]
+  }
+
+  public_deps = [
+    "//components/spellcheck/browser",
+    "//components/spellcheck/common",
+    "//components/spellcheck/renderer",
+  ]
 }
--- a/chromium_src/chrome/browser/certificate_manager_model.cc
+++ b/chromium_src/chrome/browser/certificate_manager_model.cc
@@ -37,10 +37,8 @@ net::NSSCertDatabase* GetNSSCertDatabaseForResourceContext(
    // public and private slot.
    // Redirect any slot usage to this persistent slot on Linux.
    g_nss_cert_database = new net::NSSCertDatabase(
-        crypto::ScopedPK11Slot(
-            crypto::GetPersistentNSSKeySlot()) /* public slot */,
-        crypto::ScopedPK11Slot(
-            crypto::GetPersistentNSSKeySlot()) /* private slot */);
+        crypto::ScopedPK11Slot(PK11_GetInternalKeySlot()) /* public slot */,
+        crypto::ScopedPK11Slot(PK11_GetInternalKeySlot()) /* private slot */);
  }
  return g_nss_cert_database;
 }
@@ -73,7 +71,7 @@ net::NSSCertDatabase* GetNSSCertDatabaseForResourceContext(
 void CertificateManagerModel::Create(content::BrowserContext* browser_context,
                                     const CreationCallback& callback) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);
-  base::PostTaskWithTraits(
+  base::PostTask(
      FROM_HERE, {BrowserThread::IO},
      base::BindOnce(&CertificateManagerModel::GetCertDBOnIOThread,
                     browser_context->GetResourceContext(), callback));
@@ -146,7 +144,7 @@ void CertificateManagerModel::DidGetCertDBOnIOThread(
  DCHECK_CURRENTLY_ON(BrowserThread::IO);

  bool is_user_db_available = !!cert_db->GetPublicSlot();
-  base::PostTaskWithTraits(
+  base::PostTask(
      FROM_HERE, {BrowserThread::UI},
      base::BindOnce(&CertificateManagerModel::DidGetCertDBOnUIThread, cert_db,
                     is_user_db_available, callback));
--- a/chromium_src/chrome/browser/process_singleton_posix.cc
+++ b/chromium_src/chrome/browser/process_singleton_posix.cc
@@ -56,7 +56,7 @@
 #include <stddef.h>

 #include "shell/browser/browser.h"
-#include "shell/common/atom_command_line.h"
+#include "shell/common/electron_command_line.h"

 #include "base/base_paths.h"
 #include "base/bind.h"
@@ -93,7 +93,6 @@
 #include "content/public/browser/browser_task_traits.h"
 #include "content/public/browser/browser_thread.h"
 #include "net/base/network_interfaces.h"
-#include "ui/base/l10n/l10n_util.h"

 #if defined(TOOLKIT_VIEWS) && defined(OS_LINUX) && !defined(OS_CHROMEOS)
 #include "ui/views/linux_ui/linux_ui.h"
@@ -705,7 +704,7 @@ void ProcessSingleton::LinuxWatcher::SocketReader::FinishWithACK(
  if (shutdown(fd_, SHUT_WR) < 0)
    PLOG(ERROR) << "shutdown() failed";

-  base::PostTaskWithTraits(
+  base::PostTask(
      FROM_HERE, {BrowserThread::IO},
      base::BindOnce(&ProcessSingleton::LinuxWatcher::RemoveSocketReader,
                     parent_, this));
@@ -827,7 +826,7 @@ ProcessSingleton::NotifyResult ProcessSingleton::NotifyOtherProcessWithTimeout(
    return PROCESS_NONE;
  to_send.append(current_dir.value());

-  const std::vector<std::string>& argv = electron::AtomCommandLine::argv();
+  const std::vector<std::string>& argv = electron::ElectronCommandLine::argv();
  for (std::vector<std::string>::const_iterator it = argv.begin();
       it != argv.end(); ++it) {
    to_send.push_back(kTokenDelimiter);
@@ -885,10 +884,9 @@ ProcessSingleton::NotifyResult ProcessSingleton::NotifyOtherProcessOrCreate() {

 void ProcessSingleton::StartListeningOnSocket() {
  watcher_ = new LinuxWatcher(this);
-  base::PostTaskWithTraits(
-      FROM_HERE, {BrowserThread::IO},
-      base::BindOnce(&ProcessSingleton::LinuxWatcher::StartListening, watcher_,
-                     sock_));
+  base::PostTask(FROM_HERE, {BrowserThread::IO},
+                 base::BindOnce(&ProcessSingleton::LinuxWatcher::StartListening,
+                                watcher_, sock_));
 }

 void ProcessSingleton::OnBrowserReady() {
--- a/chromium_src/chrome/browser/process_singleton_win.cc
+++ b/chromium_src/chrome/browser/process_singleton_win.cc
@@ -23,7 +23,6 @@
 #include "chrome/browser/win/chrome_process_finder.h"
 #include "content/public/common/result_codes.h"
 #include "net/base/escape.h"
-#include "ui/base/l10n/l10n_util.h"
 #include "ui/gfx/win/hwnd_util.h"

 namespace {
@@ -198,7 +197,7 @@ ProcessSingleton::NotifyResult ProcessSingleton::NotifyOtherProcess() {
    return PROCESS_NONE;
  }

-  switch (chrome::AttemptToNotifyRunningChrome(remote_window_, false)) {
+  switch (chrome::AttemptToNotifyRunningChrome(remote_window_)) {
    case chrome::NOTIFY_SUCCESS:
      return PROCESS_NOTIFIED;
    case chrome::NOTIFY_FAILED:
--- a/components/pepper_flash/BUILD.gn
+++ b/components/pepper_flash/BUILD.gn
@@ -1,61 +0,0 @@
-# Copyright (c) 2018 GitHub, Inc.
-# Use of this source code is governed by the MIT license that can be
-# found in the LICENSE file.
-
-component("pepper_flash") {
-  visibility = [ "//electron:electron_lib" ]
-  defines = [ "IS_PEPPER_FLASH_IMPL" ]
-  sources = [
-    "//chrome/browser/renderer_host/pepper/chrome_browser_pepper_host_factory.cc",
-    "//chrome/browser/renderer_host/pepper/chrome_browser_pepper_host_factory.h",
-    "//chrome/browser/renderer_host/pepper/pepper_broker_message_filter.cc",
-    "//chrome/browser/renderer_host/pepper/pepper_broker_message_filter.h",
-    "//chrome/browser/renderer_host/pepper/pepper_flash_browser_host.cc",
-    "//chrome/browser/renderer_host/pepper/pepper_flash_browser_host.h",
-    "//chrome/browser/renderer_host/pepper/pepper_flash_clipboard_message_filter.cc",
-    "//chrome/browser/renderer_host/pepper/pepper_flash_clipboard_message_filter.h",
-    "//chrome/browser/renderer_host/pepper/pepper_flash_drm_host.cc",
-    "//chrome/browser/renderer_host/pepper/pepper_flash_drm_host.h",
-    "//chrome/browser/renderer_host/pepper/pepper_isolated_file_system_message_filter.cc",
-    "//chrome/browser/renderer_host/pepper/pepper_isolated_file_system_message_filter.h",
-    "//chrome/renderer/pepper/chrome_renderer_pepper_host_factory.cc",
-    "//chrome/renderer/pepper/chrome_renderer_pepper_host_factory.h",
-    "//chrome/renderer/pepper/pepper_flash_drm_renderer_host.cc",
-    "//chrome/renderer/pepper/pepper_flash_drm_renderer_host.h",
-    "//chrome/renderer/pepper/pepper_flash_font_file_host.cc",
-    "//chrome/renderer/pepper/pepper_flash_font_file_host.h",
-    "//chrome/renderer/pepper/pepper_flash_fullscreen_host.cc",
-    "//chrome/renderer/pepper/pepper_flash_fullscreen_host.h",
-    "//chrome/renderer/pepper/pepper_flash_menu_host.cc",
-    "//chrome/renderer/pepper/pepper_flash_menu_host.h",
-    "//chrome/renderer/pepper/pepper_flash_renderer_host.cc",
-    "//chrome/renderer/pepper/pepper_flash_renderer_host.h",
-    "//chrome/renderer/pepper/pepper_helper.cc",
-    "//chrome/renderer/pepper/pepper_helper.h",
-    "//chrome/renderer/pepper/pepper_shared_memory_message_filter.cc",
-    "//chrome/renderer/pepper/pepper_shared_memory_message_filter.h",
-  ]
-  deps = [
-    "//content/public/browser",
-    "//content/public/renderer",
-    "//media:media_buildflags",
-    "//ppapi/host",
-    "//ppapi/proxy",
-    "//ppapi/proxy:ipc",
-    "//ppapi/shared_impl",
-    "//services/device/public/mojom",
-    "//skia",
-    "//third_party/adobe/flash:flapper_version_h",
-    "//ui/base",
-    "//ui/base/clipboard",
-  ]
-  if (is_mac) {
-    sources += [
-      "//chrome/browser/renderer_host/pepper/monitor_finder_mac.h",
-      "//chrome/browser/renderer_host/pepper/monitor_finder_mac.mm",
-    ]
-  }
-  if (is_linux) {
-    deps += [ "//components/services/font/public/cpp" ]
-  }
-}
--- a/default_app/index.html
+++ b/default_app/index.html
@@ -2,10 +2,9 @@

 <head>
  <title>Electron</title>
-  <meta http-equiv="Content-Security-Policy" content="default-src 'none'; script-src 'self'; style-src 'self'; img-src 'self'; connect-src 'self'" />
+  <meta http-equiv="Content-Security-Policy" content="default-src 'none'; script-src 'sha256-6PH54BfkNq/EMMhUY7nhHf3c+AxloOwfy7hWyT01CM8='; style-src 'self'; img-src 'self'; connect-src 'self'" />
  <link href="./styles.css" type="text/css" rel="stylesheet" />
  <link href="./octicon/build.css" type="text/css" rel="stylesheet" />
-  <script defer src="./index.js"></script>
 </head>

 <body>
@@ -84,6 +83,9 @@
      </div>
    </div>
  </nav>
+  <script>
+    window.electronDefaultApp.initialize()
+  </script>
 </body>

 </html>
--- a/default_app/index.ts
+++ b/default_app/index.ts
@@ -1,30 +0,0 @@
-async function getOcticonSvg (name: string) {
-  try {
-    const response = await fetch(`octicon/${name}.svg`)
-    const div = document.createElement('div')
-    div.innerHTML = await response.text()
-    return div
-  } catch {
-    return null
-  }
-}
-
-async function loadSVG (element: HTMLSpanElement) {
-  for (const cssClass of element.classList) {
-    if (cssClass.startsWith('octicon-')) {
-      const icon = await getOcticonSvg(cssClass.substr(8))
-      if (icon) {
-        for (const elemClass of element.classList) {
-          icon.classList.add(elemClass)
-        }
-        element.before(icon)
-        element.remove()
-        break
-      }
-    }
-  }
-}
-
-for (const element of document.querySelectorAll<HTMLSpanElement>('.octicon')) {
-  loadSVG(element)
-}
--- a/default_app/preload.ts
+++ b/default_app/preload.ts
@@ -1,4 +1,31 @@
-import { ipcRenderer } from 'electron'
+import { ipcRenderer, contextBridge } from 'electron'
+
+async function getOcticonSvg (name: string) {
+  try {
+    const response = await fetch(`octicon/${name}.svg`)
+    const div = document.createElement('div')
+    div.innerHTML = await response.text()
+    return div
+  } catch {
+    return null
+  }
+}
+
+async function loadSVG (element: HTMLSpanElement) {
+  for (const cssClass of element.classList) {
+    if (cssClass.startsWith('octicon-')) {
+      const icon = await getOcticonSvg(cssClass.substr(8))
+      if (icon) {
+        for (const elemClass of element.classList) {
+          icon.classList.add(elemClass)
+        }
+        element.before(icon)
+        element.remove()
+        break
+      }
+    }
+  }
+}

 async function initialize () {
  const electronPath = await ipcRenderer.invoke('bootstrap')
@@ -15,6 +42,12 @@ async function initialize () {
  replaceText('.node-version', `Node v${process.versions.node}`)
  replaceText('.v8-version', `v8 v${process.versions.v8}`)
  replaceText('.command-example', `${electronPath} path-to-app`)
+
+  for (const element of document.querySelectorAll<HTMLSpanElement>('.octicon')) {
+    loadSVG(element)
+  }
 }

-document.addEventListener('DOMContentLoaded', initialize)
+contextBridge.exposeInMainWorld('electronDefaultApp', {
+  initialize
+})
--- a/docs-translations/README.md
+++ b/docs-translations/README.md
@@ -1,33 +0,0 @@
-## Docs Translations
-
-This directory once contained unstructured translations of Electron's 
-documentation, but has been deprecated in favor of a new translation process 
-using [Crowdin], a GitHub-friendly platform for collaborative translation.
-
-For more details, visit the [electron/i18n] repo.
-
-## Contributing
-
-If you're interested in helping translate Electron's docs, visit 
-[Crowdin] and log in with your GitHub account. And thanks!
-
-## Offline Docs
-
-If you miss having access to Electron's raw markdown files in your preferred
-language, don't fret! You can still get raw docs, they're just in a 
-different place now. See [electron/i18n/tree/master/content]
-
-To more easily view and browse offline docs in your language, clone the repo and use [vmd], 
-an Electron-based GitHub-styled markdown viewer:
-
-```sh
-npm i -g vmd
-git clone https://github.com/electron/i18n
-vmd electron-i18n/content/zh-CN
-```
-
-[crowdin.com/project/electron]: https://crowdin.com/project/electron
-[Crowdin]: https://crowdin.com/project/electron
-[electron/i18n]: https://github.com/electron/i18n#readme
-[electron/i18n/tree/master/content]: https://github.com/electron/i18n/tree/master/content
-[vmd]: http://ghub.io/vmd
--- a/docs/README.md
+++ b/docs/README.md
@@ -39,6 +39,7 @@ an issue:
  * [Using Electron's APIs](tutorial/application-architecture.md#using-electron-apis)
  * [Using Node.js APIs](tutorial/application-architecture.md#using-nodejs-apis)
  * [Using Native Node.js Modules](tutorial/using-native-node-modules.md)
+  * [Performance Strategies](tutorial/performance.md)
 * Adding Features to Your App
  * [Notifications](tutorial/notifications.md)
  * [Recent Documents](tutorial/recent-documents.md)
@@ -52,6 +53,7 @@ an issue:
  * [Native File Drag & Drop](tutorial/native-file-drag-drop.md)
  * [Offscreen Rendering](tutorial/offscreen-rendering.md)
  * [Supporting macOS Dark Mode](tutorial/mojave-dark-mode-guide.md)
+  * [Web embeds in Electron](tutorial/web-embeds.md)
 * [Accessibility](tutorial/accessibility.md)
  * [Spectron](tutorial/accessibility.md#spectron)
  * [Devtron](tutorial/accessibility.md#devtron)
@@ -108,9 +110,9 @@ These individual tutorials expand on topics discussed in the guide above.

 * [Synopsis](api/synopsis.md)
 * [Process Object](api/process.md)
-* [Supported Chrome Command Line Switches](api/chrome-command-line-switches.md)
+* [Supported Command Line Switches](api/command-line-switches.md)
 * [Environment Variables](api/environment-variables.md)
-* [Breaking API Changes](api/breaking-changes.md)
+* [Breaking API Changes](breaking-changes.md)

 ### Custom DOM Elements:

@@ -134,6 +136,7 @@ These individual tutorials expand on topics discussed in the guide above.
 * [MenuItem](api/menu-item.md)
 * [net](api/net.md)
 * [netLog](api/net-log.md)
+* [Notification](api/notification.md)
 * [powerMonitor](api/power-monitor.md)
 * [powerSaveBlocker](api/power-save-blocker.md)
 * [protocol](api/protocol.md)
--- a/docs/api/accelerator.md
+++ b/docs/api/accelerator.md
@@ -18,7 +18,7 @@ method, i.e.
 ```javascript
 const { app, globalShortcut } = require('electron')

-app.on('ready', () => {
+app.whenReady().then(() => {
  // Register a 'CommandOrControl+Y' shortcut listener.
  globalShortcut.register('CommandOrControl+Y', () => {
    // Do stuff when Y and either Command/Control is pressed.
--- a/docs/api/app.md
+++ b/docs/api/app.md
@@ -34,10 +34,11 @@ Returns:

 * `launchInfo` unknown _macOS_

-Emitted when Electron has finished initializing. On macOS, `launchInfo` holds
-the `userInfo` of the `NSUserNotification` that was used to open the application,
-if it was launched from Notification Center. You can call `app.isReady()` to
-check if this event has already fired.
+Emitted once, when Electron has finished initializing. On macOS, `launchInfo`
+holds the `userInfo` of the `NSUserNotification` that was used to open the
+application, if it was launched from Notification Center. You can also call
+`app.isReady()` to check if this event has already fired and `app.whenReady()`
+to get a Promise that is fulfilled when Electron is initialized.

 ### Event: 'window-all-closed'

@@ -314,10 +315,8 @@ Returns:

 * `event` Event
 * `webContents` [WebContents](web-contents.md)
-* `request` Object
-  * `method` String
+* `authenticationResponseDetails` Object
  * `url` URL
-  * `referrer` URL
 * `authInfo` Object
  * `isProxy` Boolean
  * `scheme` String
@@ -325,8 +324,8 @@ Returns:
  * `port` Integer
  * `realm` String
 * `callback` Function
-  * `username` String
-  * `password` String
+  * `username` String (optional)
+  * `password` String (optional)

 Emitted when `webContents` wants to do basic auth.

@@ -337,12 +336,16 @@ should prevent the default behavior with `event.preventDefault()` and call
 ```javascript
 const { app } = require('electron')

-app.on('login', (event, webContents, request, authInfo, callback) => {
+app.on('login', (event, webContents, details, authInfo, callback) => {
  event.preventDefault()
  callback('username', 'secret')
 })
 ```

+If `callback` is called without a username or password, the authentication
+request will be cancelled and the authentication error will be returned to the
+page.
+
 ### Event: 'gpu-info-update'

 Emitted whenever there is a GPU info update.
@@ -485,18 +488,6 @@ Emitted when `remote.getCurrentWebContents()` is called in the renderer process
 Calling `event.preventDefault()` will prevent the object from being returned.
 Custom value can be returned by setting `event.returnValue`.

-### Event: 'remote-get-guest-web-contents'
-
-Returns:
-
-* `event` Event
-* `webContents` [WebContents](web-contents.md)
-* `guestWebContents` [WebContents](web-contents.md)
-
-Emitted when `<webview>.getWebContents()` is called in the renderer process of `webContents`.
-Calling `event.preventDefault()` will prevent the object from being returned.
-Custom value can be returned by setting `event.returnValue`.
-
 ## Methods

 The `app` object has the following methods:
@@ -555,6 +546,7 @@ app.exit(0)
 ### `app.isReady()`

 Returns `Boolean` - `true` if Electron has finished initializing, `false` otherwise.
+See also `app.whenReady()`.

 ### `app.whenReady()`

@@ -683,7 +675,7 @@ Overrides the current application's name.

 Returns `String` - The current application locale. Possible return values are documented [here](locales.md).

-To set the locale, you'll want to use a command line switch at app startup, which may be found [here](https://github.com/electron/electron/blob/master/docs/api/chrome-command-line-switches.md).
+To set the locale, you'll want to use a command line switch at app startup, which may be found [here](https://github.com/electron/electron/blob/master/docs/api/command-line-switches.md).

 **Note:** When distributing your packaged app, you have to also ship the
 `locales` folder.
@@ -770,6 +762,21 @@ macOS machine. Please refer to

 The API uses the Windows Registry and LSCopyDefaultHandlerForURLScheme internally.

+### `app.getApplicationNameForProtocol(url)`
+
+* `url` String - a URL with the protocol name to check. Unlike the other
+  methods in this family, this accepts an entire URL, including `://` at a
+  minimum (e.g. `https://`).
+
+Returns `String` - Name of the application handling the protocol, or an empty
+  string if there is no handler. For instance, if Electron is the default
+  handler of the URL, this could be `Electron` on Windows and Mac. However,
+  don't rely on the precise format which is not guaranteed to remain unchanged.
+  Expect a different format on Linux, possibly with a `.desktop` suffix.
+
+This method returns the application name of the default handler for the protocol
+(aka URI scheme) of a URL.
+
 ### `app.setUserTasks(tasks)` _Windows_

 * `tasks` [Task[]](structures/task.md) - Array of `Task` objects
@@ -930,7 +937,7 @@ if (!gotTheLock) {
  })

  // Create myWindow, load the rest of the app, etc...
-  app.on('ready', () => {
+  app.whenReady().then(() => {
  })
 }
 ```
@@ -987,6 +994,17 @@ Updates the current activity if its type matches `type`, merging the entries fro

 Changes the [Application User Model ID][app-user-model-id] to `id`.

+### `app.setActivationPolicy(policy)` _macOS_
+
+* `policy` String - Can be 'regular', 'accessory', or 'prohibited'.
+
+Sets the activation policy for a given app.
+
+Activation policy types:
+* 'regular' - The application is an ordinary app that appears in the Dock and may have a user interface.
+* 'accessory' - The application doesn’t appear in the Dock and doesn’t have a menu bar, but it may be activated programmatically or by clicking on one of its windows.
+* 'prohibited' - The application doesn’t appear in the Dock and may not create windows or be activated.
+
 ### `app.importCertificate(options, callback)` _Linux_

 * `options` Object
@@ -1186,8 +1204,9 @@ Show the app's about panel options. These options can be overridden with `app.se
  * `website` String (optional) _Linux_ - The app's website.
  * `iconPath` String (optional) _Linux_ _Windows_ - Path to the app's icon. On Linux, will be shown as 64x64 pixels while retaining aspect ratio.

-Set the about panel options. This will override the values defined in the app's
-`.plist` file on MacOS. See the [Apple docs][about-panel-options] for more details. On Linux, values must be set in order to be shown; there are no defaults.
+Set the about panel options. This will override the values defined in the app's `.plist` file on MacOS. See the [Apple docs][about-panel-options] for more details. On Linux, values must be set in order to be shown; there are no defaults.
+
+If you do not set `credits` but still wish to surface them in your app, AppKit will look for a file named "Credits.html", "Credits.rtf", and "Credits.rtfd", in that order, in the bundle returned by the NSBundle class method main. The first file found is used, and if none is found, the info area is left blank. See Apple [documentation](https://developer.apple.com/documentation/appkit/nsaboutpaneloptioncredits?language=objc) for more information.

 ### `app.isEmojiPanelSupported()`

@@ -1298,7 +1317,7 @@ command line arguments that Chromium uses.

 ### `app.dock` _macOS_ _Readonly_

-A [`Dock`](./dock.md) object that allows you to perform actions on your app icon in the user's
+A [`Dock`](./dock.md) `| undefined` object that allows you to perform actions on your app icon in the user's
 dock on macOS.

 ### `app.isPackaged` _Readonly_
--- a/docs/api/browser-view.md
+++ b/docs/api/browser-view.md
@@ -15,12 +15,9 @@ relative to its owning window. It is meant to be an alternative to the
 // In the main process.
 const { BrowserView, BrowserWindow } = require('electron')

-let win = new BrowserWindow({ width: 800, height: 600 })
-win.on('closed', () => {
-  win = null
-})
+const win = new BrowserWindow({ width: 800, height: 600 })

-let view = new BrowserView()
+const view = new BrowserView()
 win.setBrowserView(view)
 view.setBounds({ x: 0, y: 0, width: 300, height: 300 })
 view.webContents.loadURL('https://electronjs.org')
--- a/docs/api/browser-window.md
+++ b/docs/api/browser-window.md
@@ -11,10 +11,7 @@ const { BrowserWindow } = require('electron')
 // Or use `remote` from the renderer process.
 // const { BrowserWindow } = require('electron').remote

-let win = new BrowserWindow({ width: 800, height: 600 })
-win.on('closed', () => {
-  win = null
-})
+const win = new BrowserWindow({ width: 800, height: 600 })

 // Load a remote URL
 win.loadURL('https://github.com')
@@ -229,6 +226,7 @@ It creates a new `BrowserWindow` with native properties as set by the `options`.
      unless hovered over in the top left of the window. These custom buttons prevent
      issues with mouse events that occur with the standard window toolbar buttons.
      **Note:** This option is currently experimental.
+  * `trafficLightPosition` [Point](structures/point.md) (optional) - Set a custom position for the traffic light buttons. Can only be used with `titleBarStyle` set to `hidden`
  * `fullscreenWindowTitle` Boolean (optional) - Shows the title in the
    title bar in full screen mode on macOS for all `titleBarStyle` options.
    Default is `false`.
@@ -272,8 +270,6 @@ It creates a new `BrowserWindow` with native properties as set by the `options`.
      OS-level sandbox and disabling the Node.js engine. This is not the same as
      the `nodeIntegration` option and the APIs available to the preload script
      are more limited. Read more about the option [here](sandbox-option.md).
-      **Note:** This option is currently experimental and may change or be
-      removed in future Electron releases.
    * `enableRemoteModule` Boolean (optional) - Whether to enable the [`remote`](remote.md) module.
      Default is `true`.
    * `session` [Session](session.md#class-session) (optional) - Sets the session used by the
@@ -385,6 +381,8 @@ It creates a new `BrowserWindow` with native properties as set by the `options`.
    * `accessibleTitle` String (optional) - An alternative title string provided only
      to accessibility tools such as screen readers. This string is not directly
      visible to users.
+    * `spellcheck` Boolean (optional) - Whether to enable the builtin spellchecker.
+      Default is `true`.

 When setting minimum or maximum window size with `minWidth`/`maxWidth`/
 `minHeight`/`maxHeight`, it only constrains the users. It won't prevent you from
@@ -515,7 +513,7 @@ Emitted when the window is restored from a minimized state.
 Returns:

 * `event` Event
-* `newBounds` [`Rectangle`](structures/rectangle.md) - Size the window is being resized to.
+* `newBounds` [Rectangle](structures/rectangle.md) - Size the window is being resized to.

 Emitted before the window is resized. Calling `event.preventDefault()` will prevent the window from being resized.

@@ -530,7 +528,7 @@ Emitted after the window has been resized.
 Returns:

 * `event` Event
-* `newBounds` [`Rectangle`](structures/rectangle.md) - Location the window is being moved to.
+* `newBounds` [Rectangle](structures/rectangle.md) - Location the window is being moved to.

 Emitted before the window is moved. On Windows, calling `event.preventDefault()` will prevent the window from being moved.

@@ -664,7 +662,8 @@ Returns `BrowserWindow | null` - The window that is focused in this application,

 * `webContents` [WebContents](web-contents.md)

-Returns `BrowserWindow` - The window that owns the given `webContents`.
+Returns `BrowserWindow | null` - The window that owns the given `webContents`
+or `null` if the contents are not owned by a window.

 #### `BrowserWindow.fromBrowserView(browserView)`

@@ -678,7 +677,7 @@ Returns `BrowserWindow | null` - The window that owns the given `browserView`. I

 Returns `BrowserWindow` - The window with the given `id`.

-#### `BrowserWindow.addExtension(path)`
+#### `BrowserWindow.addExtension(path)` _Deprecated_

 * `path` String

@@ -689,7 +688,10 @@ The method will also not return if the extension's manifest is missing or incomp
 **Note:** This API cannot be called before the `ready` event of the `app` module
 is emitted.

-#### `BrowserWindow.removeExtension(name)`
+**Note:** This method is deprecated. Instead, use
+[`ses.loadExtension(path)`](session.md#sesloadextensionpath).
+
+#### `BrowserWindow.removeExtension(name)` _Deprecated_

 * `name` String

@@ -698,7 +700,10 @@ Remove a Chrome extension by name.
 **Note:** This API cannot be called before the `ready` event of the `app` module
 is emitted.

-#### `BrowserWindow.getExtensions()`
+**Note:** This method is deprecated. Instead, use
+[`ses.removeExtension(extension_id)`](session.md#sesremoveextensionextensionid).
+
+#### `BrowserWindow.getExtensions()` _Deprecated_

 Returns `Record<String, ExtensionInfo>` - The keys are the extension names and each value is
 an Object containing `name` and `version` properties.
@@ -706,7 +711,10 @@ an Object containing `name` and `version` properties.
 **Note:** This API cannot be called before the `ready` event of the `app` module
 is emitted.

-#### `BrowserWindow.addDevToolsExtension(path)`
+**Note:** This method is deprecated. Instead, use
+[`ses.getAllExtensions()`](session.md#sesgetallextensions).
+
+#### `BrowserWindow.addDevToolsExtension(path)` _Deprecated_

 * `path` String

@@ -722,7 +730,10 @@ The method will also not return if the extension's manifest is missing or incomp
 **Note:** This API cannot be called before the `ready` event of the `app` module
 is emitted.

-#### `BrowserWindow.removeDevToolsExtension(name)`
+**Note:** This method is deprecated. Instead, use
+[`ses.loadExtension(path)`](session.md#sesloadextensionpath).
+
+#### `BrowserWindow.removeDevToolsExtension(name)` _Deprecated_

 * `name` String

@@ -731,7 +742,10 @@ Remove a DevTools extension by name.
 **Note:** This API cannot be called before the `ready` event of the `app` module
 is emitted.

-#### `BrowserWindow.getDevToolsExtensions()`
+**Note:** This method is deprecated. Instead, use
+[`ses.removeExtension(extension_id)`](session.md#sesremoveextensionextensionid).
+
+#### `BrowserWindow.getDevToolsExtensions()` _Deprecated_

 Returns `Record<string, ExtensionInfo>` - The keys are the extension names and each value is
 an Object containing `name` and `version` properties.
@@ -748,6 +762,9 @@ console.log(installed)
 **Note:** This API cannot be called before the `ready` event of the `app` module
 is emitted.

+**Note:** This method is deprecated. Instead, use
+[`ses.getAllExtensions()`](session.md#sesgetallextensions).
+
 ### Instance Properties

 Objects created with `new BrowserWindow` have the following properties:
@@ -769,7 +786,7 @@ events.

 #### `win.id` _Readonly_

-A `Integer` property representing the unique ID of the window.
+A `Integer` property representing the unique ID of the window. Each ID is unique among all `BrowserWindow` instances of the entire Electron application.

 #### `win.autoHideMenuBar`

@@ -943,11 +960,11 @@ Returns `Boolean` - Whether the window is in simple (pre-Lion) fullscreen mode.

 Returns `Boolean` - Whether the window is in normal state (not maximized, not minimized, not in fullscreen mode).

-#### `win.setAspectRatio(aspectRatio[, extraSize])` _macOS_
+#### `win.setAspectRatio(aspectRatio[, extraSize])` _macOS_ _Linux_

 * `aspectRatio` Float - The aspect ratio to maintain for some portion of the
 content view.
-* `extraSize` [Size](structures/size.md) (optional) - The extra size not to be included while
+ * `extraSize` [Size](structures/size.md) (optional) _macOS_ - The extra size not to be included while
 maintaining the aspect ratio.

 This will make a window maintain an aspect ratio. The extra size allows a
@@ -960,13 +977,10 @@ Perhaps there are 15 pixels of controls on the left edge, 25 pixels of controls
 on the right edge and 50 pixels of controls below the player. In order to
 maintain a 16:9 aspect ratio (standard aspect ratio for HD @1920x1080) within
 the player itself we would call this function with arguments of 16/9 and
-[ 40, 50 ]. The second argument doesn't care where the extra width and height
+{ width: 40, height: 50 }. The second argument doesn't care where the extra width and height
 are within the content view--only that they exist. Sum any extra width and
 height areas you have within the overall content view.

-Calling this function with a value of `0` will remove any previously set aspect
-ratios.
-
 #### `win.setBackgroundColor(backgroundColor)`

 * `backgroundColor` String - Window's background color as a hexadecimal value,
@@ -1016,6 +1030,11 @@ console.log(win.getBounds())

 Returns [`Rectangle`](structures/rectangle.md) - The `bounds` of the window as `Object`.

+#### `win.getBackgroundColor()`
+
+Returns `String` - Gets the background color of the window. See [Setting
+`backgroundColor`](#setting-backgroundcolor).
+
 #### `win.setContentBounds(bounds[, animate])`

 * `bounds` [Rectangle](structures/rectangle.md)
@@ -1578,7 +1597,7 @@ Same as `webContents.showDefinitionForSelection()`.

 #### `win.setIcon(icon)` _Windows_ _Linux_

-* `icon` [NativeImage](native-image.md)
+* `icon` [NativeImage](native-image.md) | String

 Changes window icon.

@@ -1619,12 +1638,9 @@ can still bring up the menu bar by pressing the single `Alt` key.

 Returns `Boolean` - Whether the menu bar is visible.

-#### `win.setVisibleOnAllWorkspaces(visible[, options])`
+#### `win.setVisibleOnAllWorkspaces(visible)`

 * `visible` Boolean
-* `options` Object (optional)
-  * `visibleOnFullScreen` Boolean (optional) _macOS_ - Sets whether
-    the window should be visible above fullscreen windows

 Sets whether the window should be visible on all workspaces.

--- a/docs/api/client-request.md
+++ b/docs/api/client-request.md
@@ -32,8 +32,8 @@ the hostname and the port number 'hostname:port'.
  * `redirect` String (optional) - The redirect mode for this request. Should be
 one of `follow`, `error` or `manual`. Defaults to `follow`. When mode is `error`,
 any redirection will be aborted. When mode is `manual` the redirection will be
-deferred until [`request.followRedirect`](#requestfollowredirect) is invoked. Listen for the [`redirect`](#event-redirect) event in
-this mode to get more details about the redirect request.
+cancelled unless [`request.followRedirect`](#requestfollowredirect) is invoked
+synchronously during the [`redirect`](#event-redirect) event.

 `options` properties such as `protocol`, `host`, `hostname`, `port` and `path`
 strictly follow the Node.js model as described in the
@@ -70,8 +70,8 @@ Returns:
  * `port` Integer
  * `realm` String
 * `callback` Function
-  * `username` String
-  * `password` String
+  * `username` String (optional)
+  * `password` String (optional)

 Emitted when an authenticating proxy is asking for user credentials.

@@ -136,8 +136,11 @@ Returns:
 * `redirectUrl` String
 * `responseHeaders` Record<String, String[]>

-Emitted when there is redirection and the mode is `manual`. Calling
-[`request.followRedirect`](#requestfollowredirect) will continue with the redirection.
+Emitted when the server returns a redirect response (e.g. 301 Moved
+Permanently). Calling [`request.followRedirect`](#requestfollowredirect) will
+continue with the redirection.  If this event is handled,
+[`request.followRedirect`](#requestfollowredirect) must be called
+**synchronously**, otherwise the request will be cancelled.

 ### Instance Properties

@@ -214,7 +217,8 @@ response object,it will emit the `aborted` event.

 #### `request.followRedirect()`

-Continues any deferred redirection request when the redirection mode is `manual`.
+Continues any pending redirection. Can only be called during a `'redirect'`
+event.

 #### `request.getUploadProgress()`

--- a/docs/api/clipboard.md
+++ b/docs/api/clipboard.md
@@ -4,18 +4,12 @@

 Process: [Main](../glossary.md#main-process), [Renderer](../glossary.md#renderer-process)

-The following example shows how to write a string to the clipboard:
-
-```javascript
-const { clipboard } = require('electron')
-clipboard.writeText('Example String')
-```
-
 On Linux, there is also a `selection` clipboard. To manipulate it
 you need to pass `selection` to each method:

 ```javascript
 const { clipboard } = require('electron')
+
 clipboard.writeText('Example String', 'selection')
 console.log(clipboard.readText('selection'))
 ```
@@ -28,56 +22,106 @@ The `clipboard` module has the following methods:

 ### `clipboard.readText([type])`

-* `type` String (optional) - Can be `selection` or `clipboard`. `selection` is only available on Linux.
+* `type` String (optional) - Can be `selection` or `clipboard`; default is 'clipboard'. `selection` is only available on Linux.

 Returns `String` - The content in the clipboard as plain text.

+```js
+const { clipboard } = require('electron')
+
+clipboard.writeText('hello i am a bit of text!')
+
+const text = clipboard.readText()
+console.log(text)
+// hello i am a bit of text!'
+```
+
 ### `clipboard.writeText(text[, type])`

 * `text` String
-* `type` String (optional) - Can be `selection` or `clipboard`. `selection` is only available on Linux.
+* `type` String (optional) - Can be `selection` or `clipboard`; default is 'clipboard'. `selection` is only available on Linux.

 Writes the `text` into the clipboard as plain text.

+```js
+const { clipboard } = require('electron')
+
+const text = 'hello i am a bit of text!'
+clipboard.writeText(text)
+```
+
 ### `clipboard.readHTML([type])`

-* `type` String (optional) - Can be `selection` or `clipboard`. `selection` is only available on Linux.
+* `type` String (optional) - Can be `selection` or `clipboard`; default is 'clipboard'. `selection` is only available on Linux.

 Returns `String` - The content in the clipboard as markup.

+```js
+const { clipboard } = require('electron')
+
+clipboard.writeHTML('<b>Hi</b>')
+const html = clipboard.readHTML()
+
+console.log(html)
+// <meta charset='utf-8'><b>Hi</b>
+```
+
 ### `clipboard.writeHTML(markup[, type])`

 * `markup` String
-* `type` String (optional) - Can be `selection` or `clipboard`. `selection` is only available on Linux.
+* `type` String (optional) - Can be `selection` or `clipboard`; default is 'clipboard'. `selection` is only available on Linux.

 Writes `markup` to the clipboard.

+```js
+const { clipboard } = require('electron')
+
+clipboard.writeHTML('<b>Hi</b')
+```
+
 ### `clipboard.readImage([type])`

-* `type` String (optional) - Can be `selection` or `clipboard`. `selection` is only available on Linux.
+* `type` String (optional) - Can be `selection` or `clipboard`; default is 'clipboard'. `selection` is only available on Linux.

 Returns [`NativeImage`](native-image.md) - The image content in the clipboard.

 ### `clipboard.writeImage(image[, type])`

 * `image` [NativeImage](native-image.md)
-* `type` String (optional) - Can be `selection` or `clipboard`. `selection` is only available on Linux.
+* `type` String (optional) - Can be `selection` or `clipboard`; default is 'clipboard'. `selection` is only available on Linux.

 Writes `image` to the clipboard.

 ### `clipboard.readRTF([type])`

-* `type` String (optional) - Can be `selection` or `clipboard`. `selection` is only available on Linux.
+* `type` String (optional) - Can be `selection` or `clipboard`; default is 'clipboard'. `selection` is only available on Linux.

 Returns `String` - The content in the clipboard as RTF.

+```js
+const { clipboard } = require('electron')
+
+clipboard.writeRTF('{\\rtf1\\ansi{\\fonttbl\\f0\\fswiss Helvetica;}\\f0\\pard\nThis is some {\\b bold} text.\\par\n}')
+
+const rtf = clipboard.readRTF()
+console.log(rtf)
+// {\\rtf1\\ansi{\\fonttbl\\f0\\fswiss Helvetica;}\\f0\\pard\nThis is some {\\b bold} text.\\par\n}
+```
+
 ### `clipboard.writeRTF(text[, type])`

 * `text` String
-* `type` String (optional) - Can be `selection` or `clipboard`. `selection` is only available on Linux.
+* `type` String (optional) - Can be `selection` or `clipboard`; default is 'clipboard'. `selection` is only available on Linux.

 Writes the `text` into the clipboard in RTF.

+```js
+const { clipboard } = require('electron')
+
+const rtf = '{\\rtf1\\ansi{\\fonttbl\\f0\\fswiss Helvetica;}\\f0\\pard\nThis is some {\\b bold} text.\\par\n}'
+clipboard.writeRTF(rtf)
+```
+
 ### `clipboard.readBookmark()` _macOS_ _Windows_

 Returns `Object`:
@@ -93,7 +137,7 @@ bookmark is unavailable.

 * `title` String
 * `url` String
-* `type` String (optional) - Can be `selection` or `clipboard`. `selection` is only available on Linux.
+* `type` String (optional) - Can be `selection` or `clipboard`; default is 'clipboard'. `selection` is only available on Linux.

 Writes the `title` and `url` into the clipboard as a bookmark.

@@ -102,7 +146,9 @@ you can use `clipboard.write` to write both a bookmark and fallback text to the
 clipboard.

 ```js
-clipboard.write({
+const { clipboard } = require('electron')
+
+clipboard.writeBookmark({
  text: 'https://electronjs.org',
  bookmark: 'Electron Homepage'
 })
@@ -110,39 +156,50 @@ clipboard.write({

 ### `clipboard.readFindText()` _macOS_

-Returns `String` - The text on the find pasteboard. This method uses synchronous
-IPC when called from the renderer process. The cached value is reread from the
-find pasteboard whenever the application is activated.
+Returns `String` - The text on the find pasteboard, which is the pasteboard that holds information about the current state of the active application’s find panel.
+
+This method uses synchronous IPC when called from the renderer process.
+The cached value is reread from the find pasteboard whenever the application is activated.

 ### `clipboard.writeFindText(text)` _macOS_

 * `text` String

-Writes the `text` into the find pasteboard as plain text. This method uses
-synchronous IPC when called from the renderer process.
+Writes the `text` into the find pasteboard (the pasteboard that holds information about the current state of the active application’s find panel) as plain text. This method uses synchronous IPC when called from the renderer process.

 ### `clipboard.clear([type])`

-* `type` String (optional) - Can be `selection` or `clipboard`. `selection` is only available on Linux.
+* `type` String (optional) - Can be `selection` or `clipboard`; default is 'clipboard'. `selection` is only available on Linux.

 Clears the clipboard content.

 ### `clipboard.availableFormats([type])`

-* `type` String (optional) - Can be `selection` or `clipboard`. `selection` is only available on Linux.
+* `type` String (optional) - Can be `selection` or `clipboard`; default is 'clipboard'. `selection` is only available on Linux.

 Returns `String[]` - An array of supported formats for the clipboard `type`.

+```js
+const { clipboard } = require('electron')
+
+const formats = clipboard.availableFormats()
+console.log(formats)
+// [ 'text/plain', 'text/html' ]
+```
+
 ### `clipboard.has(format[, type])` _Experimental_

 * `format` String
-* `type` String (optional) - Can be `selection` or `clipboard`. `selection` is only available on Linux.
+* `type` String (optional) - Can be `selection` or `clipboard`; default is 'clipboard'. `selection` is only available on Linux.

 Returns `Boolean` - Whether the clipboard supports the specified `format`.

-```javascript
+```js
 const { clipboard } = require('electron')
-console.log(clipboard.has('<p>selection</p>'))
+
+const hasFormat = clipboard.has('<p>selection</p>')
+console.log(hasFormat)
+// 'true' or 'false
 ```

 ### `clipboard.read(format)` _Experimental_
@@ -157,14 +214,33 @@ Returns `String` - Reads `format` type from the clipboard.

 Returns `Buffer` - Reads `format` type from the clipboard.

+```js
+const { clipboard } = require('electron')
+
+const buffer = Buffer.from('this is binary', 'utf8')
+clipboard.writeBuffer('public.utf8-plain-text', buffer)
+
+const ret = clipboard.readBuffer('public.utf8-plain-text')
+
+console.log(buffer.equals(out))
+// true
+```
+
 ### `clipboard.writeBuffer(format, buffer[, type])` _Experimental_

 * `format` String
 * `buffer` Buffer
-* `type` String (optional) - Can be `selection` or `clipboard`. `selection` is only available on Linux.
+* `type` String (optional) - Can be `selection` or `clipboard`; default is 'clipboard'. `selection` is only available on Linux.

 Writes the `buffer` into the clipboard as `format`.

+```js
+const { clipboard } = require('electron')
+
+const buffer = Buffer.from('writeBuffer', 'utf8')
+clipboard.writeBuffer('public.utf8-plain-text', buffer)
+```
+
 ### `clipboard.write(data[, type])`

 * `data` Object
@@ -173,10 +249,29 @@ Writes the `buffer` into the clipboard as `format`.
  * `image` [NativeImage](native-image.md) (optional)
  * `rtf` String (optional)
  * `bookmark` String (optional) - The title of the URL at `text`.
-* `type` String (optional) - Can be `selection` or `clipboard`. `selection` is only available on Linux.
+* `type` String (optional) - Can be `selection` or `clipboard`; default is 'clipboard'. `selection` is only available on Linux.

-```javascript
-const { clipboard } = require('electron')
-clipboard.write({ text: 'test', html: '<b>test</b>' })
-```
 Writes `data` to the clipboard.
+
+```js
+const { clipboard } = require('electron')
+
+clipboard.write({
+  text: 'test',
+  html: '<b>Hi</b>',
+  rtf: '{\\rtf1\\utf8 text}',
+  bookmark: 'a title'
+})
+
+console.log(clipboard.readText())
+// 'test'
+
+console.log(clipboard.readHTML())
+// <meta charset='utf-8'><b>Hi</b>
+
+console.log(clipboard.readRTF())
+// '{\\rtf1\\utf8 text}'
+
+console.log(clipboard.readBookmark())
+// { title: 'a title', url: 'test' }
+```
--- a/docs/api/chrome-command-line-switches.md
+++ b/docs/api/chrome-command-line-switches.md
@@ -1,4 +1,4 @@
-# Supported Chrome Command Line Switches
+# Supported Command Line Switches

 > Command line switches supported by Electron.

@@ -11,7 +11,7 @@ const { app } = require('electron')
 app.commandLine.appendSwitch('remote-debugging-port', '8315')
 app.commandLine.appendSwitch('host-rules', 'MAP * 127.0.0.1')

-app.on('ready', () => {
+app.whenReady().then(() => {
  // Your code here
 })
 ```
@@ -181,6 +181,16 @@ logging level for all code in the source files under a `foo/bar` directory.

 This switch only works when `--enable-logging` is also passed.

+## --enable-api-filtering-logging
+
+Enables caller stack logging for the following APIs (filtering events):
+- `desktopCapturer.getSources()` / `desktop-capturer-get-sources`
+- `remote.require()` / `remote-require`
+- `remote.getGlobal()` / `remote-get-builtin`
+- `remote.getBuiltin()` / `remote-get-global`
+- `remote.getCurrentWindow()` / `remote-get-current-window`
+- `remote.getCurrentWebContents()` / `remote-get-current-web-contents`
+
 ## --no-sandbox

 Disables Chromium sandbox, which is now enabled by default.
--- a/docs/api/command-line.md
+++ b/docs/api/command-line.md
@@ -12,7 +12,7 @@ app.commandLine.hasSwitch('disable-gpu')
 ```

 For more information on what kinds of flags and switches you can use, check
-out the [Chrome Command Line Switches](./chrome-command-line-switches.md)
+out the [Command Line Switches](./command-line-switches.md)
 document.

 ### Instance Methods
--- a/docs/api/content-tracing.md
+++ b/docs/api/content-tracing.md
@@ -13,7 +13,7 @@ module is emitted.
 ```javascript
 const { app, contentTracing } = require('electron')

-app.on('ready', () => {
+app.whenReady().then(() => {
  (async () => {
    await contentTracing.startRecording({
      include_categories: ['*']
@@ -38,6 +38,9 @@ Get a set of category groups. The category groups can change as new code paths
 are reached. See also the [list of built-in tracing
 categories](https://chromium.googlesource.com/chromium/src/+/master/base/trace_event/builtin_categories.h).

+> **NOTE:** Electron adds a non-default tracing category called `"electron"`.
+> This category can be used to capture Electron-specific tracing events.
+
 ### `contentTracing.startRecording(options)`

 * `options` ([TraceConfig](structures/trace-config.md) | [TraceCategoriesAndOptions](structures/trace-categories-and-options.md))
--- a/docs/api/context-bridge.md
+++ b/docs/api/context-bridge.md
@@ -0,0 +1,112 @@
+# contextBridge
+
+> Create a safe, bi-directional, synchronous bridge across isolated contexts
+
+Process: [Renderer](../glossary.md#renderer-process)
+
+An example of exposing an API to a renderer from an isolated preload script is given below:
+
+```javascript
+// Preload (Isolated World)
+const { contextBridge, ipcRenderer } = require('electron')
+
+contextBridge.exposeInMainWorld(
+  'electron',
+  {
+    doThing: () => ipcRenderer.send('do-a-thing')
+  }
+)
+```
+
+```javascript
+// Renderer (Main World)
+
+window.electron.doThing()
+```
+
+## Glossary
+
+### Main World
+
+The "Main World" is the JavaScript context that your main renderer code runs in. By default, the
+page you load in your renderer executes code in this world.
+
+### Isolated World
+
+When `contextIsolation` is enabled in your `webPreferences`, your `preload` scripts run in an
+"Isolated World".  You can read more about context isolation and what it affects in the
+[security](../tutorial/security.md#3-enable-context-isolation-for-remote-content) docs.
+
+## Methods
+
+The `contextBridge` module has the following methods:
+
+### `contextBridge.exposeInMainWorld(apiKey, api)` _Experimental_
+
+* `apiKey` String - The key to inject the API onto `window` with.  The API will be accessible on `window[apiKey]`.
+* `api` Record<String, any> - Your API object, more information on what this API can be and how it works is available below.
+
+## Usage
+
+### API Objects
+
+The `api` object provided to [`exposeInMainWorld`](#contextbridgeexposeinmainworldapikey-api-experimental) must be an object
+whose keys are strings and values are a `Function`, `String`, `Number`, `Array`, `Boolean`, or another nested object that meets the same conditions.
+
+`Function` values are proxied to the other context and all other values are **copied** and **frozen**. Any data / primitives sent in
+the API object become immutable and updates on either side of the bridge do not result in an update on the other side.
+
+An example of a complex API object is shown below:
+
+```javascript
+const { contextBridge } = require('electron')
+
+contextBridge.exposeInMainWorld(
+  'electron',
+  {
+    doThing: () => ipcRenderer.send('do-a-thing'),
+    myPromises: [Promise.resolve(), Promise.reject(new Error('whoops'))],
+    anAsyncFunction: async () => 123,
+    data: {
+      myFlags: ['a', 'b', 'c'],
+      bootTime: 1234
+    },
+    nestedAPI: {
+      evenDeeper: {
+        youCanDoThisAsMuchAsYouWant: {
+          fn: () => ({
+            returnData: 123
+          })
+        }
+      }
+    }
+  }
+)
+```
+
+### API Functions
+
+`Function` values that you bind through the `contextBridge` are proxied through Electron to ensure that contexts remain isolated.  This
+results in some key limitations that we've outlined below.
+
+#### Parameter / Error / Return Type support
+
+Because parameters, errors and return values are **copied** when they are sent over the bridge, there are only certain types that can be used.
+At a high level, if the type you want to use can be serialized and deserialized into the same object it will work.  A table of type support
+has been included below for completeness:
+
+| Type | Complexity | Parameter Support | Return Value Support | Limitations |
+| ---- | ---------- | ----------------- | -------------------- | ----------- |
+| `String` | Simple | ✅ | ✅ | N/A |
+| `Number` | Simple | ✅ | ✅ | N/A |
+| `Boolean` | Simple | ✅ | ✅ | N/A |
+| `Object` | Complex | ✅ | ✅ | Keys must be supported using only "Simple" types in this table.  Values must be supported in this table.  Prototype modifications are dropped.  Sending custom classes will copy values but not the prototype. |
+| `Array` | Complex | ✅ | ✅ | Same limitations as the `Object` type |
+| `Error` | Complex | ✅ | ✅ | Errors that are thrown are also copied, this can result in the message and stack trace of the error changing slightly due to being thrown in a different context |
+| `Promise` | Complex | ✅ | ✅ | Promises are only proxied if they are the return value or exact parameter.  Promises nested in arrays or objects will be dropped. |
+| `Function` | Complex | ✅ | ✅ | Prototype modifications are dropped.  Sending classes or constructors will not work. |
+| [Cloneable Types](https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API/Structured_clone_algorithm) | Simple | ✅ | ✅ | See the linked document on cloneable types |
+| `Symbol` | N/A | ❌ | ❌ | Symbols cannot be copied across contexts so they are dropped |
+
+
+If the type you care about is not in the above table, it is probably not supported.
--- a/docs/api/crash-reporter.md
+++ b/docs/api/crash-reporter.md
@@ -119,6 +119,10 @@ Remove a extra parameter from the current set of parameters so that it will not

 See all of the current parameters being passed to the crash reporter.

+### `crashReporter.getCrashesDirectory()`
+
+Returns `String` - The directory where crashes are temporarily stored before being uploaded.
+
 ## Crash Report Payload

 The crash reporter will send the following data to the `submitURL` as
--- a/docs/api/debugger.md
+++ b/docs/api/debugger.md
@@ -50,7 +50,7 @@ Returns:

 * `event` Event
 * `method` String - Method name.
-* `params` unknown - Event parameters defined by the 'parameters'
+* `params` any - Event parameters defined by the 'parameters'
   attribute in the remote debugging protocol.

 Emitted whenever the debugging target issues an instrumentation event.
--- a/docs/api/desktop-capturer.md
+++ b/docs/api/desktop-capturer.md
@@ -91,7 +91,11 @@ The `desktopCapturer` module has the following methods:

 Returns `Promise<DesktopCapturerSource[]>` - Resolves with an array of [`DesktopCapturerSource`](structures/desktop-capturer-source.md) objects, each `DesktopCapturerSource` represents a screen or an individual window that can be captured.

+**Note** Capturing the screen contents requires user consent on macOS 10.15 Catalina or higher,
+which can detected by [`systemPreferences.getMediaAccessStatus`].
+
 [`navigator.mediaDevices.getUserMedia`]: https://developer.mozilla.org/en/docs/Web/API/MediaDevices/getUserMedia
+[`systemPreferences.getMediaAccessStatus`]: system-preferences.md#systempreferencesgetmediaaccessstatusmediatype-macos

 ## Caveats

--- a/docs/api/dialog.md
+++ b/docs/api/dialog.md
@@ -120,7 +120,7 @@ Returns `Promise<Object>` - Resolve with an object containing the following:

 * `canceled` Boolean - whether or not the dialog was canceled.
 * `filePaths` String[] - An array of file paths chosen by the user. If the dialog is cancelled this will be an empty array.
-* `bookmarks` String[] (optional) _macOS_ _mas_ - An array matching the `filePaths` array of base64 encoded strings which contains security scoped bookmark data. `securityScopedBookmarks` must be enabled for this to be populated.
+* `bookmarks` String[] (optional) _macOS_ _mas_ - An array matching the `filePaths` array of base64 encoded strings which contains security scoped bookmark data. `securityScopedBookmarks` must be enabled for this to be populated. (For return values, see [table here](#bookmarks-array).)

 The `browserWindow` argument allows the dialog to attach itself to a parent window, making it modal.

@@ -215,7 +215,7 @@ The `filters` specifies an array of file types that can be displayed, see
 Returns `Promise<Object>` - Resolve with an object containing the following:
  * `canceled` Boolean - whether or not the dialog was canceled.
  * `filePath` String (optional) - If the dialog is canceled, this will be `undefined`.
-  * `bookmark` String (optional) _macOS_ _mas_ - Base64 encoded string which contains the security scoped bookmark data for the saved file. `securityScopedBookmarks` must be enabled for this to be present.
+  * `bookmark` String (optional) _macOS_ _mas_ - Base64 encoded string which contains the security scoped bookmark data for the saved file. `securityScopedBookmarks` must be enabled for this to be present. (For return values, see [table here](#bookmarks-array).)

 The `browserWindow` argument allows the dialog to attach itself to a parent window, making it modal.

@@ -350,6 +350,17 @@ On Windows the options are more limited, due to the Win32 APIs used:
 * The `browserWindow` argument is ignored since it is not possible to make
   this confirmation dialog modal.

+## Bookmarks array
+
+`showOpenDialog`, `showOpenDialogSync`, `showSaveDialog`, and `showSaveDialogSync` will return a `bookmarks` array.
+
+| Build Type | securityScopedBookmarks boolean | Return Type | Return Value                   |
+|------------|---------------------------------|:-----------:|--------------------------------|
+| macOS mas  | True                            |   Success   | `['LONGBOOKMARKSTRING']`       |
+| macOS mas  | True                            |    Error    | `['']` (array of empty string) |
+| macOS mas  | False                           |      NA     | `[]` (empty array)             |
+| non mas    | any                             |      NA     | `[]` (empty array)             |
+
 ## Sheets

 On macOS, dialogs are presented as sheets attached to a window if you provide
--- a/docs/api/environment-variables.md
+++ b/docs/api/environment-variables.md
@@ -44,20 +44,32 @@ Unsupported options are:
 --use-openssl-ca
 ```

-`NODE_OPTIONS` are explicitly disallowed in packaged apps.
+`NODE_OPTIONS` are explicitly disallowed in packaged apps, except for the following:
+
+```sh
+--max-http-header-size
+--http-parser
+```

 ### `GOOGLE_API_KEY`

-You can provide an API key for making requests to Google's geocoding webservice. To do this, place the following code in your main process
-file, before opening any browser windows that will make geocoding requests:
+Geolocation support in Electron requires the use of Google Cloud Platform's
+geolocation webservice. To enable this feature, acquire a
+[Google API key](https://developers.google.com/maps/documentation/geolocation/get-api-key)
+and place the following code in your main process file, before opening any
+browser windows that will make geolocation requests:

 ```javascript
 process.env.GOOGLE_API_KEY = 'YOUR_KEY_HERE'
 ```

-For instructions on how to acquire a Google API key, visit [this page](https://developers.google.com/maps/documentation/javascript/get-api-key).
-By default, a newly generated Google API key may not be allowed to make
-geocoding requests. To enable geocoding requests, visit [this page](https://developers.google.com/maps/documentation/geocoding/get-api-key).
+By default, a newly generated Google API key may not be allowed to make geolocation requests.
+To enable the geolocation webservice for your project, enable it through the
+[API library](https://console.cloud.google.com/apis/library).
+
+N.B. You will need to add a
+[Billing Account](https://cloud.google.com/billing/docs/how-to/payment-methods#add_a_payment_method)
+to the project associated to the API key for the geolocation webservice to work.

 ### `ELECTRON_NO_ASAR`

@@ -121,5 +133,5 @@ the `electron` command to use the specified build of Electron instead of
 the one downloaded by `npm install`. Usage:

 ```sh
-export ELECTRON_OVERRIDE_DIST_PATH=/Users/username/projects/electron/out/Debug
+export ELECTRON_OVERRIDE_DIST_PATH=/Users/username/projects/electron/out/Testing
 ```
--- a/docs/api/global-shortcut.md
+++ b/docs/api/global-shortcut.md
@@ -15,7 +15,7 @@ event of the app module is emitted.
 ```javascript
 const { app, globalShortcut } = require('electron')

-app.on('ready', () => {
+app.whenReady().then(() => {
  // Register a 'CommandOrControl+X' shortcut listener.
  const ret = globalShortcut.register('CommandOrControl+X', () => {
    console.log('CommandOrControl+X is pressed')
--- a/docs/api/in-app-purchase.md
+++ b/docs/api/in-app-purchase.md
@@ -40,11 +40,17 @@ Retrieves the product descriptions.

 ### `inAppPurchase.canMakePayments()`

-Returns `Boolean`, whether a user can make a payment.
+Returns `Boolean` - whether a user can make a payment.
+
+### `inAppPurchase.restoreCompletedTransactions()`
+
+Restores finished transactions. This method can be called either to install purchases on additional devices, or to restore purchases for an application that the user deleted and reinstalled.
+
+[The payment queue](https://developer.apple.com/documentation/storekit/skpaymentqueue?language=objc) delivers a new transaction for each previously completed transaction that can be restored. Each transaction includes a copy of the original transaction.

 ### `inAppPurchase.getReceiptURL()`

-Returns `String`, the path to the receipt.
+Returns `String` - the path to the receipt.

 ### `inAppPurchase.finishAllTransactions()`

--- a/docs/api/ipc-main.md
+++ b/docs/api/ipc-main.md
@@ -77,6 +77,7 @@ only the next time a message is sent to `channel`, after which it is removed.

 * `channel` String
 * `listener` Function
+  * `...args` any[]

 Removes the specified `listener` from the listener array for the specified
 `channel`.
--- a/docs/api/ipc-renderer.md
+++ b/docs/api/ipc-renderer.md
@@ -55,9 +55,15 @@ Removes all listeners, or those of the specified `channel`.
 * `channel` String
 * `...args` any[]

-Send a message to the main process asynchronously via `channel`, you can also
-send arbitrary arguments. Arguments will be serialized as JSON internally and
-hence no functions or prototype chain will be included.
+Send an asynchronous message to the main process via `channel`, along with
+arguments. Arguments will be serialized with the [Structured Clone
+Algorithm][SCA], just like [`postMessage`][], so prototype chains will not be
+included. Sending Functions, Promises, Symbols, WeakMaps, or WeakSets will
+throw an exception.
+
+> **NOTE**: Sending non-standard JavaScript types such as DOM objects or
+> special Electron objects is deprecated, and will begin throwing an exception
+> starting with Electron 9.

 The main process handles it by listening for `channel` with the
 [`ipcMain`](ipc-main.md) module.
@@ -69,9 +75,15 @@ The main process handles it by listening for `channel` with the

 Returns `Promise<any>` - Resolves with the response from the main process.

-Send a message to the main process asynchronously via `channel` and expect an
-asynchronous result. Arguments will be serialized as JSON internally and
-hence no functions or prototype chain will be included.
+Send a message to the main process via `channel` and expect a result
+asynchronously. Arguments will be serialized with the [Structured Clone
+Algorithm][SCA], just like [`postMessage`][], so prototype chains will not be
+included. Sending Functions, Promises, Symbols, WeakMaps, or WeakSets will
+throw an exception.
+
+> **NOTE**: Sending non-standard JavaScript types such as DOM objects or
+> special Electron objects is deprecated, and will begin throwing an exception
+> starting with Electron 9.

 The main process should listen for `channel` with
 [`ipcMain.handle()`](ipc-main.md#ipcmainhandlechannel-listener).
@@ -97,15 +109,23 @@ ipcMain.handle('some-name', async (event, someArgument) => {

 Returns `any` - The value sent back by the [`ipcMain`](ipc-main.md) handler.

-Send a message to the main process synchronously via `channel`, you can also
-send arbitrary arguments. Arguments will be serialized in JSON internally and
-hence no functions or prototype chain will be included.
+Send a message to the main process via `channel` and expect a result
+synchronously. Arguments will be serialized with the [Structured Clone
+Algorithm][SCA], just like [`postMessage`][], so prototype chains will not be
+included. Sending Functions, Promises, Symbols, WeakMaps, or WeakSets will
+throw an exception.
+
+> **NOTE**: Sending non-standard JavaScript types such as DOM objects or
+> special Electron objects is deprecated, and will begin throwing an exception
+> starting with Electron 9.

 The main process handles it by listening for `channel` with [`ipcMain`](ipc-main.md) module,
 and replies by setting `event.returnValue`.

-**Note:** Sending a synchronous message will block the whole renderer process,
-unless you know what you are doing you should never use it.
+> :warning: **WARNING**: Sending a synchronous message will block the whole
+> renderer process until the reply is received, so use this method only as a
+> last resort. It's much better to use the asynchronous version,
+> [`invoke()`](ipc-renderer.md#ipcrendererinvokechannel-args).

 ### `ipcRenderer.sendTo(webContentsId, channel, ...args)`

@@ -129,3 +149,5 @@ The documentation for the `event` object passed to the `callback` can be found
 in the [`ipc-renderer-event`](structures/ipc-renderer-event.md) structure docs.

 [event-emitter]: https://nodejs.org/api/events.html#events_class_eventemitter
+[SCA]: https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API/Structured_clone_algorithm
+[`postMessage`]: https://developer.mozilla.org/en-US/docs/Web/API/Window/postMessage
--- a/docs/api/menu-item.md
+++ b/docs/api/menu-item.md
@@ -14,7 +14,7 @@ See [`Menu`](menu.md) for examples.
    * `menuItem` MenuItem
    * `browserWindow` [BrowserWindow](browser-window.md)
    * `event` [KeyboardEvent](structures/keyboard-event.md)
-  * `role` String (optional) - Can be `undo`, `redo`, `cut`, `copy`, `paste`, `pasteAndMatchStyle`, `delete`, `selectAll`, `reload`, `forceReload`, `toggleDevTools`, `resetZoom`, `zoomIn`, `zoomOut`, `togglefullscreen`, `window`, `minimize`, `close`, `help`, `about`, `services`, `hide`, `hideOthers`, `unhide`, `quit`, `startSpeaking`, `stopSpeaking`, `close`, `minimize`, `zoom`, `front`, `appMenu`, `fileMenu`, `editMenu`, `viewMenu`, `recentDocuments`, `toggleTabBar`, `selectNextTab`, `selectPreviousTab`, `mergeAllWindows`, `clearRecentDocuments`, `moveTabToNewWindow` or `windowMenu` - Define the action of the menu item, when specified the
+  * `role` String (optional) - Can be `undo`, `redo`, `cut`, `copy`, `paste`, `pasteAndMatchStyle`, `delete`, `selectAll`, `reload`, `forceReload`, `toggleDevTools`, `resetZoom`, `zoomIn`, `zoomOut`, `togglefullscreen`, `window`, `minimize`, `close`, `help`, `about`, `services`, `hide`, `hideOthers`, `unhide`, `quit`, `startSpeaking`, `stopSpeaking`, `minimize`, `zoom`, `front`, `appMenu`, `fileMenu`, `editMenu`, `viewMenu`, `recentDocuments`, `toggleTabBar`, `selectNextTab`, `selectPreviousTab`, `mergeAllWindows`, `clearRecentDocuments`, `moveTabToNewWindow` or `windowMenu` - Define the action of the menu item, when specified the
    `click` property will be ignored. See [roles](#roles).
  * `type` String (optional) - Can be `normal`, `separator`, `submenu`, `checkbox` or
    `radio`.
@@ -130,8 +130,7 @@ dynamically changed.

 #### `menuItem.label`

-A `String` indicating the item's visible label, this property can be
-dynamically changed.
+A `String` indicating the item's visible label.

 #### `menuItem.click`

@@ -165,7 +164,7 @@ item's icon, if set.

 #### `menuItem.sublabel`

-A `String` indicating the item's sublabel, this property can be dynamically changed.
+A `String` indicating the item's sublabel.

 #### `menuItem.toolTip` _macOS_

@@ -197,7 +196,9 @@ You can add a `click` function for additional behavior.
 #### `menuItem.registerAccelerator`

 A `Boolean` indicating if the accelerator should be registered with the
-system or just displayed, this property can be dynamically changed.
+system or just displayed.
+
+This property can be dynamically changed.

 #### `menuItem.commandId`

--- a/docs/api/modernization/promisification.md
+++ b/docs/api/modernization/promisification.md
@@ -1,17 +1,6 @@
 ## Promisification

-The Electron team is currently undergoing an initiative to convert callback-based functions in Electron to return Promises. During this transition period, both the callback and Promise-based versions of these functions will work correctly, and will both be documented.
-
-To enable deprecation warnings for these updated functions, use the [`process.enablePromiseAPIs` runtime flag](../process.md#processenablepromiseapis).
-
-When a majority of affected functions are migrated, this flag will be enabled by default and all developers will be able to see these deprecation warnings. At that time, the callback-based versions will also be removed from documentation. This document will be continuously updated as more functions are converted.
-
-### Candidate Functions
-
- [app.importCertificate(options, callback)](https://github.com/electron/electron/blob/master/docs/api/app.md#importCertificate)
- [contents.print([options], [callback])](https://github.com/electron/electron/blob/master/docs/api/web-contents.md#print)
-
-### Converted Functions
+The Electron team recently underwent an initiative to convert callback-based APIs to Promise-based ones. See converted functions below:

 - [app.getFileIcon(path[, options], callback)](https://github.com/electron/electron/blob/master/docs/api/app.md#getFileIcon)
 - [contents.capturePage([rect, ]callback)](https://github.com/electron/electron/blob/master/docs/api/web-contents.md#capturePage)
--- a/docs/api/native-image.md
+++ b/docs/api/native-image.md
@@ -329,9 +329,9 @@ can be called on empty images.

 [buffer]: https://nodejs.org/api/buffer.html#buffer_class_buffer

-## Properties
+### Instance Properties

-### `nativeImage.isMacTemplateImage` _macOS_
+#### `nativeImage.isMacTemplateImage` _macOS_

 A `Boolean` property that determines whether the image is considered a [template image](https://developer.apple.com/documentation/appkit/nsimage/1520017-template).

--- a/docs/api/native-theme.md
+++ b/docs/api/native-theme.md
@@ -27,7 +27,7 @@ should use `themeSource` below.

 ### `nativeTheme.themeSource`

-A `String` property that can be `system`, `light` or `dark`.  It is used to override and supercede
+A `String` property that can be `system`, `light` or `dark`.  It is used to override and supersede
 the value that Chromium has chosen to use internally.

 Setting this property to `system` will remove the override and
--- a/docs/api/net-log.md
+++ b/docs/api/net-log.md
@@ -7,7 +7,7 @@ Process: [Main](../glossary.md#main-process)
 ```javascript
 const { netLog } = require('electron')

-app.on('ready', async () => {
+app.whenReady().then(async () => {
  await netLog.startLogging('/path/to/net-log')
  // After some network events
  const path = await netLog.stopLogging()
@@ -15,7 +15,7 @@ app.on('ready', async () => {
 })
 ```

-See [`--log-net-log`](chrome-command-line-switches.md#--log-net-logpath) to log network events throughout the app's lifecycle.
+See [`--log-net-log`](command-line-switches.md#--log-net-logpath) to log network events throughout the app's lifecycle.

 **Note:** All methods unless specified can only be used after the `ready` event
 of the `app` module gets emitted.
--- a/docs/api/net.md
+++ b/docs/api/net.md
@@ -28,7 +28,7 @@ Example usage:

 ```javascript
 const { app } = require('electron')
-app.on('ready', () => {
+app.whenReady().then(() => {
  const { net } = require('electron')
  const request = net.request('https://github.com')
  request.on('response', (response) => {
--- a/docs/api/notification.md
+++ b/docs/api/notification.md
@@ -35,8 +35,10 @@ Returns `Boolean` - Whether or not desktop notifications are supported on the cu
  * `silent` Boolean (optional) - Whether or not to emit an OS notification noise when showing the notification.
  * `icon` (String | [NativeImage](native-image.md)) (optional) - An icon to use in the notification.
  * `hasReply` Boolean (optional) _macOS_ - Whether or not to add an inline reply option to the notification.
+  * `timeoutType` String (optional) _Linux_ _Windows_ - The timeout duration of the notification. Can be 'default' or 'never'.
  * `replyPlaceholder` String (optional) _macOS_ - The placeholder to write in the inline reply input field.
  * `sound` String (optional) _macOS_ - The name of the sound file to play when the notification is shown.
+  * `urgency` String (optional) _Linux_ - The urgency level of the notification. Can be 'normal', 'critical', or 'low'.
  * `actions` [NotificationAction[]](structures/notification-action.md) (optional) _macOS_ - Actions to add to the notification. Please read the available actions and limitations in the `NotificationAction` documentation.
  * `closeButtonText` String (optional) _macOS_ - A custom title for the close button of an alert. An empty string will cause the default localized text to be used.

@@ -144,6 +146,18 @@ A `Boolean` property representing whether the notification is silent.

 A `Boolean` property representing whether the notification has a reply action.

+#### `notification.urgency` _Linux_
+
+A `String` property representing the urgency level of the notification. Can be 'normal', 'critical', or 'low'.
+
+Default is 'low' - see [NotifyUrgency](https://developer.gnome.org/notification-spec/#urgency-levels) for more information.
+
+#### `notification.timeoutType` _Linux_ _Windows_
+
+A `String` property representing the type of timeout duration for the notification. Can be 'default' or 'never'.
+
+If `timeoutType` is set to 'never', the notification never expires. It stays open until closed by the calling API or the user.
+
 #### `notification.actions`

 A [`NotificationAction[]`](structures/notification-action.md) property representing the actions of the notification.
--- a/docs/api/power-monitor.md
+++ b/docs/api/power-monitor.md
@@ -13,7 +13,7 @@ For example:
 ```javascript
 const { app, powerMonitor } = require('electron')

-app.on('ready', () => {
+app.whenReady().then(() => {
  powerMonitor.on('suspend', () => {
    console.log('The system is going to sleep')
  })
--- a/docs/api/process.md
+++ b/docs/api/process.md
@@ -82,12 +82,6 @@ A `Boolean` that controls whether or not deprecation warnings are printed to `st
 Setting this to `true` will silence deprecation warnings. This property is used
 instead of the `--no-deprecation` command line flag.

-### `process.enablePromiseAPIs`
-
-A `Boolean` that controls whether or not deprecation warnings are printed to `stderr` when
-formerly callback-based APIs converted to Promises are invoked using callbacks. Setting this to `true`
-will enable deprecation warnings.
-
 ### `process.resourcesPath` _Readonly_

 A `String` representing the path to the resources directory.
@@ -217,11 +211,15 @@ that all statistics are reported in Kilobytes.

 Returns `String` - The version of the host operating system.

-Examples:
+Example:

-* `macOS` -> `10.13.6`
-* `Windows` -> `10.0.17763`
-* `Linux` -> `4.15.0-45-generic`
+```js
+const version = process.getSystemVersion()
+console.log(version)
+// On macOS -> '10.13.6'
+// On Windows -> '10.0.17763'
+// On Linux -> '4.15.0-45-generic'
+```

 **Note:** It returns the actual operating system version instead of kernel version on macOS unlike `os.release()`.

--- a/docs/api/protocol-ns.md
+++ b/docs/api/protocol-ns.md
@@ -20,7 +20,7 @@ An example of implementing a protocol that has the same effect as the
 const { app, protocol } = require('electron')
 const path = require('path')

-app.on('ready', () => {
+app.whenReady().then(() => {
  protocol.registerFileProtocol('atom', (request, callback) => {
    const url = request.url.substr(7)
    callback({ path: path.normalize(`${__dirname}/${url}`) })
@@ -47,7 +47,7 @@ to register it to that session explicitly.
 const { session, app, protocol } = require('electron')
 const path = require('path')

-app.on('ready', () => {
+app.whenReady().then(() => {
  const partition = 'persist:example'
  const ses = session.fromPartition(partition)

--- a/docs/api/protocol.md
+++ b/docs/api/protocol.md
@@ -11,7 +11,7 @@ An example of implementing a protocol that has the same effect as the
 const { app, protocol } = require('electron')
 const path = require('path')

-app.on('ready', () => {
+app.whenReady().then(() => {
  protocol.registerFileProtocol('atom', (request, callback) => {
    const url = request.url.substr(7)
    callback({ path: path.normalize(`${__dirname}/${url}`) })
@@ -34,7 +34,7 @@ To have your custom protocol work in combination with a custom session, you need
 const { session, app, protocol } = require('electron')
 const path = require('path')

-app.on('ready', () => {
+app.whenReady().then(() => {
  const partition = 'persist:example'
  const ses = session.fromPartition(partition)

@@ -389,9 +389,7 @@ which sends a `Buffer` as a response.
      * `url` String
      * `method` String (optional)
      * `session` Session | null (optional)
-      * `uploadData` Object (optional)
-        * `contentType` String - MIME type of the content.
-        * `data` String - Content to be sent.
+      * `uploadData` [ProtocolResponseUploadData](structures/protocol-response-upload-data.md) (optional)
 * `completion` Function (optional)
  * `error` Error

--- a/docs/api/remote.md
+++ b/docs/api/remote.md
@@ -163,7 +163,7 @@ project/
 ```js
 // main process: main/index.js
 const { app } = require('electron')
-app.on('ready', () => { /* ... */ })
+app.whenReady().then(() => { /* ... */ })
 ```

 ```js
--- a/docs/api/sandbox-option.md
+++ b/docs/api/sandbox-option.md
@@ -39,7 +39,7 @@ To create a sandboxed window, pass `sandbox: true` to `webPreferences`:

 ```js
 let win
-app.on('ready', () => {
+app.whenReady().then(() => {
  win = new BrowserWindow({
    webPreferences: {
      sandbox: true
@@ -59,7 +59,7 @@ and returns a proxy to this via `window.open`).
 ```js
 let win
 app.enableSandbox()
-app.on('ready', () => {
+app.whenReady().then(() => {
  // no need to pass `sandbox: true` since `app.enableSandbox()` was called.
  win = new BrowserWindow()
  win.loadURL('http://google.com')
@@ -73,7 +73,7 @@ Here's an example:

 ```js
 let win
-app.on('ready', () => {
+app.whenReady().then(() => {
  win = new BrowserWindow({
    webPreferences: {
      sandbox: true,
--- a/docs/api/screen.md
+++ b/docs/api/screen.md
@@ -18,7 +18,7 @@ An example of creating a window that fills the whole screen:
 const { app, BrowserWindow, screen } = require('electron')

 let win
-app.on('ready', () => {
+app.whenReady().then(() => {
  const { width, height } = screen.getPrimaryDisplay().workAreaSize
  win = new BrowserWindow({ width, height })
  win.loadURL('https://github.com')
@@ -32,7 +32,7 @@ const { app, BrowserWindow, screen } = require('electron')

 let win

-app.on('ready', () => {
+app.whenReady().then(() => {
  let displays = screen.getAllDisplays()
  let externalDisplay = displays.find((display) => {
    return display.bounds.x !== 0 || display.bounds.y !== 0
--- a/docs/api/session.md
+++ b/docs/api/session.md
@@ -126,9 +126,10 @@ Clears the session’s HTTP cache.
    `scheme://host:port`.
  * `storages` String[] (optional) - The types of storages to clear, can contain:
    `appcache`, `cookies`, `filesystem`, `indexdb`, `localstorage`,
-    `shadercache`, `websql`, `serviceworkers`, `cachestorage`.
+    `shadercache`, `websql`, `serviceworkers`, `cachestorage`. If not
+    specified, clear all storage types.
  * `quotas` String[] (optional) - The types of quotas to clear, can contain:
-    `temporary`, `persistent`, `syncable`.
+    `temporary`, `persistent`, `syncable`. If not specified, clear all quotas.

 Returns `Promise<void>` - resolves when the storage data has been cleared.

@@ -271,6 +272,7 @@ the original network configuration.
  * `request` Object
    * `hostname` String
    * `certificate` [Certificate](structures/certificate.md)
+    * `validatedCertificate` [Certificate](structures/certificate.md)
    * `verificationResult` String - Verification result from chromium.
    * `errorCode` Integer - Error code.
  * `callback` Function
@@ -456,10 +458,111 @@ this session just before normal `preload` scripts run.
 Returns `String[]` an array of paths to preload scripts that have been
 registered.

+#### `ses.setSpellCheckerLanguages(languages)`
+
+* `languages` String[] - An array of language codes to enable the spellchecker for.
+
+The built in spellchecker does not automatically detect what language a user is typing in.  In order for the
+spell checker to correctly check their words you must call this API with an array of language codes.  You can
+get the list of supported language codes with the `ses.availableSpellCheckerLanguages` property.
+
+**Note:** On macOS the OS spellchecker is used and will detect your language automatically.  This API is a no-op on macOS.
+
+#### `ses.getSpellCheckerLanguages()`
+
+Returns `String[]` - An array of language codes the spellchecker is enabled for.  If this list is empty the spellchecker
+will fallback to using `en-US`.  By default on launch if this setting is an empty list Electron will try to populate this
+setting with the current OS locale.  This setting is persisted across restarts.
+
+**Note:** On macOS the OS spellchecker is used and has it's own list of languages.  This API is a no-op on macOS.
+
+#### `ses.setSpellCheckerDictionaryDownloadURL(url)`
+
+* `url` String - A base URL for Electron to download hunspell dictionaries from.
+
+By default Electron will download hunspell dictionaries from the Chromium CDN.  If you want to override this
+behavior you can use this API to point the dictionary downloader at your own hosted version of the hunspell
+dictionaries.  We publish a `hunspell_dictionaries.zip` file with each release which contains the files you need
+to host here.
+
+**Note:** On macOS the OS spellchecker is used and therefore we do not download any dictionary files.  This API is a no-op on macOS.
+
+#### `ses.addWordToSpellCheckerDictionary(word)`
+
+* `word` String - The word you want to add to the dictionary
+
+Returns `Boolean` - Whether the word was successfully written to the custom dictionary.
+
+**Note:** On macOS and Windows 10 this word will be written to the OS custom dictionary as well
+
+#### `ses.loadExtension(path)`
+
+* `path` String - Path to a directory containing an unpacked Chrome extension
+
+Returns `Promise<Extension>` - resolves when the extension is loaded.
+
+This method will raise an exception if the extension could not be loaded. If
+there are warnings when installing the extension (e.g. if the extension
+requests an API that Electron does not support) then they will be logged to the
+console.
+
+Note that Electron does not support the full range of Chrome extensions APIs.
+
+Note that in previous versions of Electron, extensions that were loaded would
+be remembered for future runs of the application. This is no longer the case:
+`loadExtension` must be called on every boot of your app if you want the
+extension to be loaded.
+
+```js
+const { app, session } = require('electron')
+const path = require('path')
+
+app.on('ready', async () => {
+  await session.defaultSession.loadExtension(path.join(__dirname, 'react-devtools'))
+  // Note that in order to use the React DevTools extension, you'll need to
+  // download and unzip a copy of the extension.
+})
+```
+
+This API does not support loading packed (.crx) extensions.
+
+**Note:** This API cannot be called before the `ready` event of the `app` module
+is emitted.
+
+#### `ses.removeExtension(extensionId)`
+
+* `extensionId` String - ID of extension to remove
+
+Unloads an extension.
+
+**Note:** This API cannot be called before the `ready` event of the `app` module
+is emitted.
+
+#### `ses.getExtension(extensionId)`
+
+* `extensionId` String - ID of extension to query
+
+Returns `Extension` | `null` - The loaded extension with the given ID.
+
+**Note:** This API cannot be called before the `ready` event of the `app` module
+is emitted.
+
+#### `ses.getAllExtensions()`
+
+Returns `Extension[]` - A list of all loaded extensions.
+
+**Note:** This API cannot be called before the `ready` event of the `app` module
+is emitted.
+
 ### Instance Properties

 The following properties are available on instances of `Session`:

+#### `ses.availableSpellCheckerLanguages` _Readonly_
+
+A `String[]` array which consists of all the known available spell checker languages.  Providing a language
+code to the `setSpellCheckerLanaguages` API that isn't in this array will result in an error.
+
 #### `ses.cookies` _Readonly_

 A [`Cookies`](cookies.md) object for this session.
@@ -476,12 +579,12 @@ A [`Protocol`](protocol.md) object for this session.
 const { app, session } = require('electron')
 const path = require('path')

-app.on('ready', function () {
+app.whenReady().then(() => {
  const protocol = session.fromPartition('some-partition').protocol
-  protocol.registerFileProtocol('atom', function (request, callback) {
-    var url = request.url.substr(7)
+  protocol.registerFileProtocol('atom', (request, callback) => {
+    let url = request.url.substr(7)
    callback({ path: path.normalize(`${__dirname}/${url}`) })
-  }, function (error) {
+  }, (error) => {
    if (error) console.error('Failed to register protocol')
  })
 })
@@ -494,7 +597,7 @@ A [`NetLog`](net-log.md) object for this session.
 ```javascript
 const { app, session } = require('electron')

-app.on('ready', async function () {
+app.whenReady().then(async () => {
  const netLog = session.fromPartition('some-partition').netLog
  netLog.startLogging('/path/to/net-log')
  // After some network events
--- a/docs/api/shell.md
+++ b/docs/api/shell.md
@@ -24,11 +24,11 @@ The `shell` module has the following methods:

 Show the given file in a file manager. If possible, select the file.

-### `shell.openItem(fullPath)`
+### `shell.openPath(path)`

-* `fullPath` String
+* `path` String

-Returns `Boolean` - Whether the item was successfully opened.
+Returns `Promise<String>` - Resolves with an string containing the error message corresponding to the failure if a failure occurred, otherwise "".

 Open the given file in the desktop's default manner.

--- a/docs/api/structures/extension.md
+++ b/docs/api/structures/extension.md
@@ -0,0 +1,5 @@
+# Extension Object
+
+* `id` String
+* `name` String
+* `version` String
--- a/docs/api/structures/ipc-main-event.md
+++ b/docs/api/structures/ipc-main-event.md
@@ -4,4 +4,5 @@
 * `returnValue` any - Set this to the value to be returned in a synchronous message
 * `sender` WebContents - Returns the `webContents` that sent the message
 * `reply` Function - A function that will send an IPC message to the renderer frame that sent the original message that you are currently handling.  You should use this method to "reply" to the sent message in order to guarantee the reply will go to the correct process and frame.
+  * `channel` String
  * `...args` any[]
--- a/docs/api/structures/printer-info.md
+++ b/docs/api/structures/printer-info.md
@@ -1,9 +1,13 @@
 # PrinterInfo Object

-* `name` String
-* `description` String
-* `status` Number
-* `isDefault` Boolean
+* `name` String - the name of the printer as understood by the OS.
+* `displayName` String - the name of the printer as shown in Print Preview.
+* `description` String - a longer description of the printer's type.
+* `status` Number - the current status of the printer.
+* `isDefault` Boolean - whether or not a given printer is set as the default printer on the OS.
+* `options` Object - an object containing a variable number of platform-specific printer information.
+
+The number represented by `status` means different things on different platforms: on Windows it's potential values can be found [here](https://docs.microsoft.com/en-us/windows/win32/printdocs/printer-info-2), and on Linux and macOS they can be found [here](https://www.cups.org/doc/cupspm.html).

 ## Example

@@ -12,13 +16,14 @@ may be different on each platform.

 ```javascript
 {
-  name: 'Zebra_LP2844',
-  description: 'Zebra LP2844',
+  name: 'Austin_4th_Floor_Printer___C02XK13BJHD4',
+  displayName: 'Austin 4th Floor Printer @ C02XK13BJHD4',
+  description: 'TOSHIBA ColorMFP',
  status: 3,
  isDefault: false,
  options: {
    copies: '1',
-    'device-uri': 'usb://Zebra/LP2844?location=14200000',
+    'device-uri': 'dnssd://Austin%204th%20Floor%20Printer%20%40%20C02XK13BJHD4._ipps._tcp.local./?uuid=71687f1e-1147-3274-6674-22de61b110bd',
    finishings: '3',
    'job-cancel-after': '10800',
    'job-hold-until': 'no-hold',
@@ -26,18 +31,19 @@ may be different on each platform.
    'job-sheets': 'none,none',
    'marker-change-time': '0',
    'number-up': '1',
-    'printer-commands': 'none',
-    'printer-info': 'Zebra LP2844',
+    'printer-commands': 'ReportLevels,PrintSelfTestPage,com.toshiba.ColourProfiles.update,com.toshiba.EFiling.update,com.toshiba.EFiling.checkPassword',
+    'printer-info': 'Austin 4th Floor Printer @ C02XK13BJHD4',
    'printer-is-accepting-jobs': 'true',
-    'printer-is-shared': 'true',
+    'printer-is-shared': 'false',
+    'printer-is-temporary': 'false',
    'printer-location': '',
-    'printer-make-and-model': 'Zebra EPL2 Label Printer',
+    'printer-make-and-model': 'TOSHIBA ColorMFP',
    'printer-state': '3',
-    'printer-state-change-time': '1484872644',
-    'printer-state-reasons': 'offline-report',
-    'printer-type': '36932',
-    'printer-uri-supported': 'ipp://localhost/printers/Zebra_LP2844',
-    system_driverinfo: 'Z'
+    'printer-state-change-time': '1573472937',
+    'printer-state-reasons': 'offline-report,com.toshiba.snmp.failed',
+    'printer-type': '10531038',
+    'printer-uri-supported': 'ipp://localhost/printers/Austin_4th_Floor_Printer___C02XK13BJHD4',
+    system_driverinfo: 'T'
  }
 }
 ```
--- a/docs/api/structures/protocol-response-upload-data.md
+++ b/docs/api/structures/protocol-response-upload-data.md
@@ -1,4 +1,4 @@
 # ProtocolResponseUploadData Object

 * `contentType` String - MIME type of the content.
-* `data` String - Content to be sent.
+* `data` String | Buffer - Content to be sent.
--- a/docs/api/structures/shared-worker-info.md
+++ b/docs/api/structures/shared-worker-info.md
@@ -0,0 +1,4 @@
+# SharedWorkerInfo Object
+
+* `id` String - The unique id of the shared worker.
+* `url` String - The url of the shared worker.
--- a/docs/api/synopsis.md
+++ b/docs/api/synopsis.md
@@ -22,7 +22,7 @@ The main process script is like a normal Node.js script:
 const { app, BrowserWindow } = require('electron')
 let win = null

-app.on('ready', () => {
+app.whenReady().then(() => {
  win = new BrowserWindow({ width: 800, height: 600 })
  win.loadURL('https://github.com')
 })
@@ -56,7 +56,7 @@ const { app, BrowserWindow } = require('electron')

 let win

-app.on('ready', () => {
+app.whenReady().then(() => {
  win = new BrowserWindow()
  win.loadURL('https://github.com')
 })
@@ -71,7 +71,7 @@ const { app, BrowserWindow } = electron

 let win

-app.on('ready', () => {
+app.whenReady().then(() => {
  win = new BrowserWindow()
  win.loadURL('https://github.com')
 })
@@ -85,7 +85,7 @@ const app = electron.app
 const BrowserWindow = electron.BrowserWindow
 let win

-app.on('ready', () => {
+app.whenReady().then(() => {
  win = new BrowserWindow()
  win.loadURL('https://github.com')
 })
--- a/docs/api/system-preferences.md
+++ b/docs/api/system-preferences.md
@@ -291,7 +291,7 @@ This API is only available on macOS 10.14 Mojave or newer.
    * `window-frame` - Window frame.
    * `window-text` - Text in windows.
  * On **macOS**
-    * `alternate-selected-control-text` - The text on a selected surface in a list or table.
+    * `alternate-selected-control-text` - The text on a selected surface in a list or table. _deprecated_
    * `control-background` - The background of a large interface element, such as a browser or table.
    * `control` - The surface of a control.
    * `control-text` -The text of a control that isn’t disabled.
@@ -310,7 +310,7 @@ This API is only available on macOS 10.14 Mojave or newer.
    * `selected-content-background` - The background for selected content in a key window or view.
    * `selected-control` - The surface of a selected control.
    * `selected-control-text` - The text of a selected control.
-    * `selected-menu-item` - The text of a selected menu.
+    * `selected-menu-item-text` - The text of a selected menu.
    * `selected-text-background` - The background of selected text.
    * `selected-text` - Selected text.
    * `separator` - A separator between different sections of content.
@@ -328,6 +328,8 @@ This API is only available on macOS 10.14 Mojave or newer.
 Returns `String` - The system color setting in RGB hexadecimal form (`#ABCDEF`).
 See the [Windows docs][windows-colors] and the [MacOS docs][macos-colors] for more details.

+The following colors are only available on macOS 10.14: `find-highlight`, `selected-content-background`, `separator`, `unemphasized-selected-content-background`, `unemphasized-selected-text-background`, and `unemphasized-selected-text`.
+
 [windows-colors]:https://msdn.microsoft.com/en-us/library/windows/desktop/ms724371(v=vs.85).aspx
 [macos-colors]:https://developer.apple.com/design/human-interface-guidelines/macos/visual-design/color#dynamic-system-colors

@@ -432,11 +434,13 @@ Returns `Boolean` - `true` if the current process is a trusted accessibility cli

 ### `systemPreferences.getMediaAccessStatus(mediaType)` _macOS_

-* `mediaType` String - `microphone` or `camera`.
+* `mediaType` String - Can be `microphone`, `camera` or `screen`.

 Returns `String` - Can be `not-determined`, `granted`, `denied`, `restricted` or `unknown`.

-This user consent was not required until macOS 10.14 Mojave, so this method will always return `granted` if your system is running 10.13 High Sierra or lower.
+This user consent was not required on macOS 10.13 High Sierra or lower so this method will always return `granted`.
+macOS 10.14 Mojave or higher requires consent for `microphone` and `camera` access.
+macOS 10.15 Catalina or higher requires consent for `screen` access.

 ### `systemPreferences.askForMediaAccess(mediaType)` _macOS_

--- a/docs/api/touch-bar-button.md
+++ b/docs/api/touch-bar-button.md
@@ -8,16 +8,24 @@ Process: [Main](../tutorial/application-architecture.md#main-and-renderer-proces

 * `options` Object
  * `label` String (optional) - Button text.
+  * `accessibilityLabel` String (optional) - A short description of the button for use by screenreaders like VoiceOver.
  * `backgroundColor` String (optional) - Button background color in hex format,
    i.e `#ABCDEF`.
  * `icon` [NativeImage](native-image.md) | String (optional) - Button icon.
  * `iconPosition` String (optional) - Can be `left`, `right` or `overlay`. Defaults to `overlay`.
  * `click` Function (optional) - Function to call when the button is clicked.
+  * `enabled` Boolean (optional) - Whether the button is in an enabled state.  Default is `true`.
+
+When defining `accessibilityLabel`, ensure you have considered macOS [best practices](https://developer.apple.com/documentation/appkit/nsaccessibilitybutton/1524910-accessibilitylabel?language=objc).

 ### Instance Properties

 The following properties are available on instances of `TouchBarButton`:

+#### `touchBarButton.accessibilityLabel`
+
+A `String` representing the description of the button to be read by a screen reader. Will only be read by screen readers if no label is set.
+
 #### `touchBarButton.label`

 A `String` representing the button's current text. Changing this value immediately updates the button
@@ -32,3 +40,7 @@ the button in the touch bar.

 A `NativeImage` representing the button's current icon. Changing this value immediately updates the button
 in the touch bar.
+
+#### `touchBarButton.enabled`
+
+A `Boolean` representing whether the button is in an enabled state.
--- a/docs/api/touch-bar-label.md
+++ b/docs/api/touch-bar-label.md
@@ -8,8 +8,11 @@ Process: [Main](../tutorial/application-architecture.md#main-and-renderer-proces

 * `options` Object
  * `label` String (optional) - Text to display.
+  * `accessibilityLabel` String (optional) - A short description of the button for use by screenreaders like VoiceOver.
  * `textColor` String (optional) - Hex color of text, i.e `#ABCDEF`.

+When defining `accessibilityLabel`, ensure you have considered macOS [best practices](https://developer.apple.com/documentation/appkit/nsaccessibilitybutton/1524910-accessibilitylabel?language=objc).
+
 ### Instance Properties

 The following properties are available on instances of `TouchBarLabel`:
@@ -19,6 +22,10 @@ The following properties are available on instances of `TouchBarLabel`:
 A `String` representing the label's current text. Changing this value immediately updates the label in
 the touch bar.

+#### `touchBarLabel.accessibilityLabel`
+
+A `String` representing the description of the label to be read by a screen reader.
+
 #### `touchBarLabel.textColor`

 A `String` hex code representing the label's current text color. Changing this value immediately updates the
--- a/docs/api/touch-bar.md
+++ b/docs/api/touch-bar.md
@@ -166,7 +166,7 @@ const touchBar = new TouchBar({

 let window

-app.once('ready', () => {
+app.whenReady().then(() => {
  window = new BrowserWindow({
    frame: false,
    titleBarStyle: 'hiddenInset',
--- a/docs/api/tray.md
+++ b/docs/api/tray.md
@@ -10,7 +10,7 @@ Process: [Main](../glossary.md#main-process)
 const { app, Menu, Tray } = require('electron')

 let tray = null
-app.on('ready', () => {
+app.whenReady().then(() => {
  tray = new Tray('/path/to/my/icon')
  const contextMenu = Menu.buildFromTemplate([
    { label: 'Item1', type: 'radio' },
@@ -38,7 +38,7 @@ __Platform limitations:__
 const { app, Menu, Tray } = require('electron')

 let appIcon = null
-app.on('ready', () => {
+app.whenReady().then(() => {
  appIcon = new Tray('/path/to/my/icon')
  const contextMenu = Menu.buildFromTemplate([
    { label: 'Item1', type: 'radio' },
@@ -58,9 +58,10 @@ If you want to keep exact same behaviors on all platforms, you should not
 rely on the `click` event and always attach a context menu to the tray icon.


-### `new Tray(image)`
+### `new Tray(image, [guid])`

 * `image` ([NativeImage](native-image.md) | String)
+* `guid` String (optional) _Windows_ - Assigns a GUID to the tray icon. If the executable is signed and the signature contains an organization in the subject line then the GUID is permanently associated with that signature. OS level settings like the position of the tray icon in the system tray will persist even if the path to the executable changes. If the executable is not code-signed then the GUID is permanently associated with the path to the executable. Changing the path to the executable will break the creation of the tray icon and a new GUID must be used. However, it is highly recommended to use the GUID parameter only in conjunction with code-signed executable. If an App defines multiple tray icons then each icon must use a separate GUID.

 Creates a new tray icon associated with the `image`.

@@ -143,6 +144,26 @@ Emitted when a drag operation exits the tray icon.

 Emitted when a drag operation ends on the tray or ends at another location.

+#### Event: 'mouse-up' _macOS_
+
+Returns:
+
+* `event` [KeyboardEvent](structures/keyboard-event.md)
+* `position` [Point](structures/point.md) - The position of the event.
+
+Emitted when the mouse is released from clicking the tray icon.
+
+Note: This will not be emitted if you have set a context menu for your Tray using `tray.setContextMenu`, as a result of macOS-level constraints.
+
+#### Event: 'mouse-down' _macOS_
+
+Returns:
+
+* `event` [KeyboardEvent](structures/keyboard-event.md)
+* `position` [Point](structures/point.md) - The position of the event.
+
+Emitted when the mouse clicks the tray icon.
+
 #### Event: 'mouse-enter' _macOS_

 Returns:
@@ -257,6 +278,10 @@ be shown instead of the tray icon's context menu.

 The `position` is only available on Windows, and it is (0, 0) by default.

+#### `tray.closeContextMenu()` _macOS_ _Windows_
+
+Closes an open context menu, as set by `tray.setContextMenu()`.
+
 #### `tray.setContextMenu(menu)`

 * `menu` Menu | null
--- a/docs/api/web-contents.md
+++ b/docs/api/web-contents.md
@@ -454,10 +454,8 @@ The usage is the same with [the `select-client-certificate` event of
 Returns:

 * `event` Event
-* `request` Object
-  * `method` String
+* `authenticationResponseDetails` Object
  * `url` URL
-  * `referrer` URL
 * `authInfo` Object
  * `isProxy` Boolean
  * `scheme` String
@@ -465,8 +463,8 @@ Returns:
  * `port` Integer
  * `realm` String
 * `callback` Function
-  * `username` String
-  * `password` String
+  * `username` String (optional)
+  * `password` String (optional)

 Emitted when `webContents` wants to do basic auth.

@@ -570,6 +568,9 @@ Returns:
  * `titleText` String - Title or alt text of the selection that the context
    was invoked on.
  * `misspelledWord` String - The misspelled word under the cursor, if any.
+  * `dictionarySuggestions` String[] - An array of suggested words to show the
+    user to replace the `misspelledWord`.  Only available if there is a misspelled
+    word and spellchecker is enabled.
  * `frameCharset` String - The character encoding of the frame on which the
    menu was invoked.
  * `inputFieldType` String - If the context menu was invoked on an input
@@ -623,7 +624,7 @@ const { app, BrowserWindow } = require('electron')
 let win = null
 app.commandLine.appendSwitch('enable-experimental-web-platform-features')

-app.on('ready', () => {
+app.whenReady().then(() => {
  win = new BrowserWindow({ width: 800, height: 600 })
  win.webContents.on('select-bluetooth-device', (event, deviceList, callback) => {
    event.preventDefault()
@@ -705,8 +706,7 @@ Returns:
 * `line` Integer
 * `sourceId` String

-Emitted when the associated window logs a console message. Will not be emitted
-for windows with *offscreen rendering* enabled.
+Emitted when the associated window logs a console message.

 #### Event: 'preload-error'

@@ -800,17 +800,6 @@ Emitted when `remote.getCurrentWebContents()` is called in the renderer process.
 Calling `event.preventDefault()` will prevent the object from being returned.
 Custom value can be returned by setting `event.returnValue`.

-#### Event: 'remote-get-guest-web-contents'
-
-Returns:
-
-* `event` IpcMainEvent
-* `guestWebContents` [WebContents](web-contents.md)
-
-Emitted when `<webview>.getWebContents()` is called in the renderer process.
-Calling `event.preventDefault()` will prevent the object from being returned.
-Custom value can be returned by setting `event.returnValue`.
-
 ### Instance Methods

 #### `contents.loadURL(url[, options])`
@@ -998,7 +987,7 @@ Injects CSS into the current web page and returns a unique key for the inserted
 stylesheet.

 ```js
-contents.on('did-finish-load', function () {
+contents.on('did-finish-load', () => {
  contents.insertCSS('html, body { background-color: #f00; }')
 })
 ```
@@ -1013,7 +1002,7 @@ Removes the inserted CSS from the current web page. The stylesheet is identified
 by its key, which is returned from `contents.insertCSS(css)`.

 ```js
-contents.on('did-finish-load', async function () {
+contents.on('did-finish-load', async () => {
  const key = await contents.insertCSS('html, body { background-color: #f00; }')
  contents.removeInsertedCSS(key)
 })
@@ -1042,6 +1031,17 @@ contents.executeJavaScript('fetch("https://jsonplaceholder.typicode.com/users/1"
  })
 ```

+#### `contents.executeJavaScriptInIsolatedWorld(worldId, scripts[, userGesture])`
+
+* `worldId` Integer - The ID of the world to run the javascript in, `0` is the default world, `999` is the world used by Electron's `contextIsolation` feature.  You can provide any integer here.
+* `scripts` [WebSource[]](structures/web-source.md)
+* `userGesture` Boolean (optional) - Default is `false`.
+
+Returns `Promise<any>` - A promise that resolves with the result of the executed code
+or is rejected if the result of the code is a rejected promise.
+
+Works like `executeJavaScript` but evaluates `scripts` in an isolated context.
+
 #### `contents.setIgnoreMenuShortcuts(ignore)` _Experimental_

 * `ignore` Boolean
@@ -1113,15 +1113,6 @@ Sets the maximum and minimum pinch-to-zoom level.
 > contents.setVisualZoomLevelLimits(1, 3)
 > ```

-#### `contents.setLayoutZoomLevelLimits(minimumLevel, maximumLevel)`
-
-* `minimumLevel` Number
-* `maximumLevel` Number
-
-Returns `Promise<void>`
-
-Sets the maximum and minimum layout-based (i.e. non-visual) zoom level.
-
 #### `contents.undo()`

 Executes the editing command `undo` in web page.
@@ -1234,11 +1225,34 @@ Returns `Promise<NativeImage>` - Resolves with a [NativeImage](native-image.md)

 Captures a snapshot of the page within `rect`. Omitting `rect` will capture the whole visible page.

+#### `contents.isBeingCaptured()`
+
+Returns `Boolean` - Whether this page is being captured. It returns true when the capturer count
+is large then 0.
+
+#### `contents.incrementCapturerCount([size, stayHidden])`
+
+* `size` [Size](structures/size.md) (optional) - The perferred size for the capturer.
+* `stayHidden` Boolean (optional) -  Keep the page hidden instead of visible.
+
+Increase the capturer count by one. The page is considered visible when its browser window is
+hidden and the capturer count is non-zero. If you would like the page to stay hidden, you should ensure that `stayHidden` is set to true.
+
+This also affects the Page Visibility API.
+
+#### `contents.decrementCapturerCount([stayHidden])`
+
+* `stayHidden` Boolean (optional) -  Keep the page in hidden state instead of visible.
+
+Decrease the capturer count by one. The page will be set to hidden or occluded state when its
+browser window is hidden or occluded and the capturer count reaches zero. If you want to
+decrease the hidden capturer count instead you should set `stayHidden` to true.
+
 #### `contents.getPrinters()`

 Get the system printer list.

-Returns [`PrinterInfo[]`](structures/printer-info.md).
+Returns [`PrinterInfo[]`](structures/printer-info.md)

 #### `contents.print([options], [callback])`

@@ -1246,7 +1260,7 @@ Returns [`PrinterInfo[]`](structures/printer-info.md).
  * `silent` Boolean (optional) - Don't ask user for print settings. Default is `false`.
  * `printBackground` Boolean (optional) - Prints the background color and image of
    the web page. Default is `false`.
-  * `deviceName` String (optional) - Set the printer device name to use. Default is `''`.
+  * `deviceName` String (optional) - Set the printer device name to use. Must be the system-defined name and not the 'friendly' name, e.g 'Brother_QL_820NWB' and not 'Brother QL-820NWB'.
  * `color` Boolean (optional) - Set whether the printed web page will be in color or grayscale. Default is `true`.
  * `margins` Object (optional)
    * `marginType` String (optional) - Can be `default`, `none`, `printableArea`, or `custom`. If `custom` is chosen, you will also need to specify `top`, `bottom`, `left`, and `right`.
@@ -1259,13 +1273,17 @@ Returns [`PrinterInfo[]`](structures/printer-info.md).
  * `pagesPerSheet` Number (optional) - The number of pages to print per page sheet.
  * `collate` Boolean (optional) - Whether the web page should be collated.
  * `copies` Number (optional) - The number of copies of the web page to print.
-  * `pageRanges` Record<string, number> (optional) - The page range to print. Should have two keys: `from` and `to`.
+  * `pageRanges` Record<string, number> (optional) - The page range to print.
+    * `from` Number - the start page.
+    * `to` Number - the end page.
  * `duplexMode` String (optional) - Set the duplex mode of the printed web page. Can be `simplex`, `shortEdge`, or `longEdge`.
-  * `dpi` Object (optional)
+  * `dpi` Record<string, number> (optional)
    * `horizontal` Number (optional) - The horizontal dpi.
    * `vertical` Number (optional) - The vertical dpi.
  * `header` String (optional) - String to be printed as page header.
  * `footer` String (optional) - String to be printed as page footer.
+  * `pageSize` String | Size (optional) - Specify page size of the printed document. Can be `A3`,
+  `A4`, `A5`, `Legal`, `Letter`, `Tabloid` or an Object containing `height`.
 * `callback` Function (optional)
  * `success` Boolean - Indicates success of the print call.
  * `failureReason` String - Called back if the print fails; can be `cancelled` or `failed`.
@@ -1287,14 +1305,21 @@ win.webContents.print(options, (success, errorType) => {
 #### `contents.printToPDF(options)`

 * `options` Object
+  * `headerFooter` Record<string, string> (optional) - the header and footer for the PDF.
+    * `title` String - The title for the PDF header.
+    * `url` String - the url for the PDF footer.
+  * `landscape` Boolean (optional) - `true` for landscape, `false` for portrait.
  * `marginsType` Integer (optional) - Specifies the type of margins to use. Uses 0 for
    default margin, 1 for no margin, and 2 for minimum margin.
-  * `pageSize` String | Size (optional) - Specify page size of the generated PDF. Can be `A3`,
-    `A4`, `A5`, `Legal`, `Letter`, `Tabloid` or an Object containing `height`
    and `width` in microns.
+  * `scaleFactor` Number (optional) - The scale factor of the web page. Can range from 0 to 100.
+  * `pageRanges` Record<string, number> (optional) - The page range to print.
+    * `from` Number - the first page to print.
+    * `to` Number - the last page to print (inclusive).
+  * `pageSize` String | Size (optional) - Specify page size of the generated PDF. Can be `A3`,
+  `A4`, `A5`, `Legal`, `Letter`, `Tabloid` or an Object containing `height`
  * `printBackground` Boolean (optional) - Whether to print CSS backgrounds.
  * `printSelectionOnly` Boolean (optional) - Whether to print selection only.
-  * `landscape` Boolean (optional) - `true` for landscape, `false` for portrait.

 Returns `Promise<Buffer>` - Resolves with the generated PDF data.

@@ -1310,7 +1335,9 @@ By default, an empty `options` will be regarded as:
  marginsType: 0,
  printBackground: false,
  printSelectionOnly: false,
-  landscape: false
+  landscape: false,
+  pageSize: 'A4',
+  scaleFactor: 100
 }
 ```

@@ -1327,12 +1354,13 @@ win.loadURL('http://github.com')

 win.webContents.on('did-finish-load', () => {
  // Use default printing options
-  win.webContents.printToPDF({}, (error, data) => {
-    if (error) throw error
+  win.webContents.printToPDF({}).then(data => {
    fs.writeFile('/tmp/print.pdf', data, (error) => {
      if (error) throw error
      console.log('Write PDF successfully.')
    })
+  }).catch(error => {
+    console.log(error)
  })
 })
 ```
@@ -1389,13 +1417,20 @@ An example of showing devtools in a `<webview>` tag:
 </head>
 <body>
  <webview id="browser" src="https://github.com"></webview>
-  <webview id="devtools"></webview>
+  <webview id="devtools" src="about:blank"></webview>
  <script>
+    const { webContents } = require('electron').remote
+    const emittedOnce = (element, eventName) => new Promise(resolve => {
+      element.addEventListener(eventName, event => resolve(event), { once: true })
+    })
    const browserView = document.getElementById('browser')
    const devtoolsView = document.getElementById('devtools')
-    browserView.addEventListener('dom-ready', () => {
-      const browser = browserView.getWebContents()
-      browser.setDevToolsWebContents(devtoolsView.getWebContents())
+    const browserReady = emittedOnce(browserView, 'dom-ready')
+    const devtoolsReady = emittedOnce(devtoolsView, 'dom-ready')
+    Promise.all([browserReady, devtoolsReady]).then(() => {
+      const browser = webContents.fromId(browserView.getWebContentsId())
+      const devtools = webContents.fromId(devtoolsView.getWebContentsId())
+      browser.setDevToolsWebContents(devtools)
      browser.openDevTools()
    })
  </script>
@@ -1411,7 +1446,7 @@ const { app, BrowserWindow } = require('electron')
 let win = null
 let devtools = null

-app.once('ready', () => {
+app.whenReady().then(() => {
  win = new BrowserWindow()
  devtools = new BrowserWindow()
  win.loadURL('https://github.com')
@@ -1461,6 +1496,16 @@ Starts inspecting element at position (`x`, `y`).

 Opens the developer tools for the shared worker context.

+#### `contents.inspectSharedWorkerById(workerId)`
+
+* `workerId` String
+
+Inspects the shared worker based on its ID.
+
+#### `contents.getAllSharedWorkers()`
+
+Returns [`SharedWorkerInfo[]`](structures/shared-worker-info.md) - Information about all Shared Workers.
+
 #### `contents.inspectServiceWorker()`

 Opens the developer tools for the service worker context.
@@ -1470,9 +1515,15 @@ Opens the developer tools for the service worker context.
 * `channel` String
 * `...args` any[]

-Send an asynchronous message to renderer process via `channel`, you can also
-send arbitrary arguments. Arguments will be serialized in JSON internally and
-hence no functions or prototype chain will be included.
+Send an asynchronous message to the renderer process via `channel`, along with
+arguments. Arguments will be serialized with the [Structured Clone
+Algorithm][SCA], just like [`postMessage`][], so prototype chains will not be
+included. Sending Functions, Promises, Symbols, WeakMaps, or WeakSets will
+throw an exception.
+
+> **NOTE**: Sending non-standard JavaScript types such as DOM objects or
+> special Electron objects is deprecated, and will begin throwing an exception
+> starting with Electron 9.

 The renderer process can handle the message by listening to `channel` with the
 [`ipcRenderer`](ipc-renderer.md) module.
@@ -1484,7 +1535,7 @@ An example of sending messages from the main process to the renderer process:
 const { app, BrowserWindow } = require('electron')
 let win = null

-app.on('ready', () => {
+app.whenReady().then(() => {
  win = new BrowserWindow({ width: 800, height: 600 })
  win.loadURL(`file://${__dirname}/index.html`)
  win.webContents.on('did-finish-load', () => {
@@ -1513,8 +1564,14 @@ app.on('ready', () => {
 * `...args` any[]

 Send an asynchronous message to a specific frame in a renderer process via
-`channel`. Arguments will be serialized
-as JSON internally and as such no functions or prototype chains will be included.
+`channel`, along with arguments. Arguments will be serialized with the
+[Structured Clone Algorithm][SCA], just like [`postMessage`][], so prototype
+chains will not be included. Sending Functions, Promises, Symbols, WeakMaps, or
+WeakSets will throw an exception.
+
+> **NOTE**: Sending non-standard JavaScript types such as DOM objects or
+> special Electron objects is deprecated, and will begin throwing an exception
+> starting with Electron 9.

 The renderer process can handle the message by listening to `channel` with the
 [`ipcRenderer`](ipc-renderer.md) module.
@@ -1753,7 +1810,7 @@ Only applicable if *offscreen rendering* is enabled.

 #### `contents.id` _Readonly_

-A `Integer` representing the unique ID of this WebContents.
+A `Integer` representing the unique ID of this WebContents. Each ID is unique among all `WebContents` instances of the entire Electron application.

 #### `contents.session` _Readonly_

@@ -1776,3 +1833,5 @@ A [`Debugger`](debugger.md) instance for this webContents.

 [keyboardevent]: https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEvent
 [event-emitter]: https://nodejs.org/api/events.html#events_class_eventemitter
+[SCA]: https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API/Structured_clone_algorithm
+[`postMessage`]: https://developer.mozilla.org/en-US/docs/Web/API/Window/postMessage
--- a/docs/api/web-frame.md
+++ b/docs/api/web-frame.md
@@ -56,13 +56,6 @@ Sets the maximum and minimum pinch-to-zoom level.
 > webFrame.setVisualZoomLevelLimits(1, 3)
 > ```

-### `webFrame.setLayoutZoomLevelLimits(minimumLevel, maximumLevel)`
-
-* `minimumLevel` Number
-* `maximumLevel` Number
-
-Sets the maximum and minimum layout-based (i.e. non-visual) zoom level.
-
 ### `webFrame.setSpellCheckProvider(language, provider)`

 * `language` String
@@ -74,6 +67,17 @@ Sets the maximum and minimum layout-based (i.e. non-visual) zoom level.

 Sets a provider for spell checking in input fields and text areas.

+If you want to use this method you must disable the builtin spellchecker when you
+construct the window.
+
+```js
+const mainWindow = new BrowserWindow({
+  webPreferences: {
+    spellcheck: false
+  }
+})
+```
+
 The `provider` must be an object that has a `spellCheck` method that accepts
 an array of individual words for spellchecking.
 The `spellCheck` function runs asynchronously and calls the `callback` function
--- a/docs/api/web-request.md
+++ b/docs/api/web-request.md
@@ -146,7 +146,7 @@ response are visible by the time this listener is fired.
    * `timestamp` Double
    * `statusLine` String
    * `statusCode` Integer
-    * `responseHeaders` Record<string, string> (optional)
+    * `responseHeaders` Record<string, string[]> (optional)
  * `callback` Function
    * `headersReceivedResponse` Object
      * `cancel` Boolean (optional)
@@ -175,7 +175,7 @@ The `callback` has to be called with a `response` object.
    * `resourceType` String
    * `referrer` String
    * `timestamp` Double
-    * `responseHeaders` Record<string, string> (optional)
+    * `responseHeaders` Record<string, string[]> (optional)
    * `fromCache` Boolean - Indicates whether the response was fetched from disk
      cache.
    * `statusCode` Integer
@@ -205,7 +205,7 @@ and response headers are available.
    * `ip` String (optional) - The server IP address that the request was
      actually sent to.
    * `fromCache` Boolean
-    * `responseHeaders` Record<string, string> (optional)
+    * `responseHeaders` Record<string, string[]> (optional)

 The `listener` will be called with `listener(details)` when a server initiated
 redirect is about to occur.
@@ -224,7 +224,7 @@ redirect is about to occur.
    * `resourceType` String
    * `referrer` String
    * `timestamp` Double
-    * `responseHeaders` Record<string, string> (optional)
+    * `responseHeaders` Record<string, string[]> (optional)
    * `fromCache` Boolean
    * `statusCode` Integer
    * `statusLine` String
--- a/docs/api/webview-tag.md
+++ b/docs/api/webview-tag.md
@@ -545,9 +545,32 @@ Stops any `findInPage` request for the `webview` with the provided `action`.

 * `options` Object (optional)
  * `silent` Boolean (optional) - Don't ask user for print settings. Default is `false`.
-  * `printBackground` Boolean (optional) - Also prints the background color and image of
+  * `printBackground` Boolean (optional) - Prints the background color and image of
    the web page. Default is `false`.
-  * `deviceName` String (optional) - Set the printer device name to use. Default is `''`.
+  * `deviceName` String (optional) - Set the printer device name to use. Must be the system-defined name and not the 'friendly' name, e.g 'Brother_QL_820NWB' and not 'Brother QL-820NWB'.
+  * `color` Boolean (optional) - Set whether the printed web page will be in color or grayscale. Default is `true`.
+  * `margins` Object (optional)
+    * `marginType` String (optional) - Can be `default`, `none`, `printableArea`, or `custom`. If `custom` is chosen, you will also need to specify `top`, `bottom`, `left`, and `right`.
+    * `top` Number (optional) - The top margin of the printed web page, in pixels.
+    * `bottom` Number (optional) - The bottom margin of the printed web page, in pixels.
+    * `left` Number (optional) - The left margin of the printed web page, in pixels.
+    * `right` Number (optional) - The right margin of the printed web page, in pixels.
+  * `landscape` Boolean (optional) - Whether the web page should be printed in landscape mode. Default is `false`.
+  * `scaleFactor` Number (optional) - The scale factor of the web page.
+  * `pagesPerSheet` Number (optional) - The number of pages to print per page sheet.
+  * `collate` Boolean (optional) - Whether the web page should be collated.
+  * `copies` Number (optional) - The number of copies of the web page to print.
+  * `pageRanges` Record<string, number> (optional) - The page range to print.
+    * `from` Number - the start page.
+    * `to` Number - the end page.
+  * `duplexMode` String (optional) - Set the duplex mode of the printed web page. Can be `simplex`, `shortEdge`, or `longEdge`.
+  * `dpi` Record<string, number> (optional)
+    * `horizontal` Number (optional) - The horizontal dpi.
+    * `vertical` Number (optional) - The vertical dpi.
+  * `header` String (optional) - String to be printed as page header.
+  * `footer` String (optional) - String to be printed as page footer.
+  * `pageSize` String | Size (optional) - Specify page size of the printed document. Can be `A3`,
+  `A4`, `A5`, `Legal`, `Letter`, `Tabloid` or an Object containing `height`.

 Returns `Promise<void>`

@@ -556,16 +579,23 @@ Prints `webview`'s web page. Same as `webContents.print([options])`.
 ### `<webview>.printToPDF(options)`

 * `options` Object
+  * `headerFooter` Record<string, string> (optional) - the header and footer for the PDF.
+    * `title` String - The title for the PDF header.
+    * `url` String - the url for the PDF footer.
+  * `landscape` Boolean (optional) - `true` for landscape, `false` for portrait.
  * `marginsType` Integer (optional) - Specifies the type of margins to use. Uses 0 for
    default margin, 1 for no margin, and 2 for minimum margin.
-  * `pageSize` String | Size (optional) - Specify page size of the generated PDF. Can be `A3`,
-    `A4`, `A5`, `Legal`, `Letter`, `Tabloid` or an Object containing `height`
    and `width` in microns.
+  * `scaleFactor` Number (optional) - The scale factor of the web page. Can range from 0 to 100.
+  * `pageRanges` Record<string, number> (optional) - The page range to print.
+    * `from` Number - the first page to print.
+    * `to` Number - the last page to print (inclusive).
+  * `pageSize` String | Size (optional) - Specify page size of the generated PDF. Can be `A3`,
+  `A4`, `A5`, `Legal`, `Letter`, `Tabloid` or an Object containing `height`
  * `printBackground` Boolean (optional) - Whether to print CSS backgrounds.
  * `printSelectionOnly` Boolean (optional) - Whether to print selection only.
-  * `landscape` Boolean (optional) - `true` for landscape, `false` for portrait.

-Returns `Promise<Buffer>` - Resolves with the generated PDF data.
+Returns `Promise<Uint8Array>` - Resolves with the generated PDF data.

 Prints `webview`'s web page as PDF, Same as `webContents.printToPDF(options)`.

@@ -635,27 +665,10 @@ Returns `Promise<void>`

 Sets the maximum and minimum pinch-to-zoom level.

-### `<webview>.setLayoutZoomLevelLimits(minimumLevel, maximumLevel)`
-
-* `minimumLevel` Number
-* `maximumLevel` Number
-
-Returns `Promise<void>`
-
-Sets the maximum and minimum layout-based (i.e. non-visual) zoom level.
-
 ### `<webview>.showDefinitionForSelection()` _macOS_

 Shows pop-up dictionary that searches the selected word on the page.

-### `<webview>.getWebContents()`
-
-Returns [`WebContents`](web-contents.md) - The web contents associated with
-this `webview`.
-
-It depends on the [`remote`](remote.md) module,
-it is therefore not available when this module is disabled.
-
 ### `<webview>.getWebContentsId()`

 Returns `Number` - The WebContents ID of this `webview`.
--- a/docs/api/breaking-changes-ns.md
+++ b/docs/api/breaking-changes-ns.md
--- a/docs/api/breaking-changes.md
+++ b/docs/api/breaking-changes.md
@@ -1,11 +1,151 @@
 # Breaking Changes

-Breaking changes will be documented here, and deprecation warnings added to JS code where possible, at least [one major version](../tutorial/electron-versioning.md#semver) before the change is made.
+Breaking changes will be documented here, and deprecation warnings added to JS code where possible, at least [one major version](tutorial/electron-versioning.md#semver) before the change is made.

 ## `FIXME` comments

 The `FIXME` string is used in code comments to denote things that should be fixed for future releases. See https://github.com/electron/electron/search?q=fixme

+## Planned Breaking API Changes (9.0)
+
+### `<webview>.getWebContents()`
+
+This API, which was deprecated in Electron 8.0, is now removed.
+
+```js
+// Removed in Electron 9.0
+webview.getWebContents()
+// Replace with
+const { remote } = require('electron')
+remote.webContents.fromId(webview.getWebContentsId())
+```
+
+### `webFrame.setLayoutZoomLevelLimits()`
+
+Chromium has removed support for changing the layout zoom level limits, and it
+is beyond Electron's capacity to maintain it. The function was deprecated in
+Electron 8.x, and has been removed in Electron 9.x. The layout zoom level limits
+are now fixed at a minimum of 0.25 and a maximum of 5.0, as defined
+[here](https://chromium.googlesource.com/chromium/src/+/938b37a6d2886bf8335fc7db792f1eb46c65b2ae/third_party/blink/common/page/page_zoom.cc#11).
+
+### Sending non-JS objects over IPC now throws an exception
+
+In Electron 8.0, IPC was changed to use the Structured Clone Algorithm,
+bringing significant performance improvements. To help ease the transition, the
+old IPC serialization algorithm was kept and used for some objects that aren't
+serializable with Structured Clone. In particular, DOM objects (e.g. `Element`,
+`Location` and `DOMMatrix`), Node.js objects backed by C++ classes (e.g.
+`process.env`, some members of `Stream`), and Electron objects backed by C++
+classes (e.g. `WebContents`, `BrowserWindow` and `WebFrame`) are not
+serializable with Structured Clone. Whenever the old algorithm was invoked, a
+deprecation warning was printed.
+
+In Electron 9.0, the old serialization algorithm has been removed, and sending
+such non-serializable objects will now throw an "object could not be cloned"
+error.
+
+## Planned Breaking API Changes (8.0)
+
+### Values sent over IPC are now serialized with Structured Clone Algorithm
+
+The algorithm used to serialize objects sent over IPC (through
+`ipcRenderer.send`, `ipcRenderer.sendSync`, `WebContents.send` and related
+methods) has been switched from a custom algorithm to V8's built-in [Structured
+Clone Algorithm][SCA], the same algorithm used to serialize messages for
+`postMessage`. This brings about a 2x performance improvement for large
+messages, but also brings some breaking changes in behavior.
+
+- Sending Functions, Promises, WeakMaps, WeakSets, or objects containing any
+  such values, over IPC will now throw an exception, instead of silently
+  converting the functions to `undefined`.
+```js
+// Previously:
+ipcRenderer.send('channel', { value: 3, someFunction: () => {} })
+// => results in { value: 3 } arriving in the main process
+
+// From Electron 8:
+ipcRenderer.send('channel', { value: 3, someFunction: () => {} })
+// => throws Error("() => {} could not be cloned.")
+```
+- `NaN`, `Infinity` and `-Infinity` will now be correctly serialized, instead
+  of being converted to `null`.
+- Objects containing cyclic references will now be correctly serialized,
+  instead of being converted to `null`.
+- `Set`, `Map`, `Error` and `RegExp` values will be correctly serialized,
+  instead of being converted to `{}`.
+- `BigInt` values will be correctly serialized, instead of being converted to
+  `null`.
+- Sparse arrays will be serialized as such, instead of being converted to dense
+  arrays with `null`s.
+- `Date` objects will be transferred as `Date` objects, instead of being
+  converted to their ISO string representation.
+- Typed Arrays (such as `Uint8Array`, `Uint16Array`, `Uint32Array` and so on)
+  will be transferred as such, instead of being converted to Node.js `Buffer`.
+- Node.js `Buffer` objects will be transferred as `Uint8Array`s. You can
+  convert a `Uint8Array` back to a Node.js `Buffer` by wrapping the underlying
+  `ArrayBuffer`:
+```js
+Buffer.from(value.buffer, value.byteOffset, value.byteLength)
+```
+
+Sending any objects that aren't native JS types, such as DOM objects (e.g.
+`Element`, `Location`, `DOMMatrix`), Node.js objects (e.g. `process.env`,
+`Stream`), or Electron objects (e.g. `WebContents`, `BrowserWindow`,
+`WebFrame`) is deprecated. In Electron 8, these objects will be serialized as
+before with a DeprecationWarning message, but starting in Electron 9, sending
+these kinds of objects will throw a 'could not be cloned' error.
+
+[SCA]: https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API/Structured_clone_algorithm
+
+### `<webview>.getWebContents()`
+
+This API is implemented using the `remote` module, which has both performance
+and security implications. Therefore its usage should be explicit.
+
+```js
+// Deprecated
+webview.getWebContents()
+// Replace with
+const { remote } = require('electron')
+remote.webContents.fromId(webview.getWebContentsId())
+```
+
+However, it is recommended to avoid using the `remote` module altogether.
+
+```js
+// main
+const { ipcMain, webContents } = require('electron')
+
+const getGuestForWebContents = (webContentsId, contents) => {
+  const guest = webContents.fromId(webContentsId)
+  if (!guest) {
+    throw new Error(`Invalid webContentsId: ${webContentsId}`)
+  }
+  if (guest.hostWebContents !== contents) {
+    throw new Error(`Access denied to webContents`)
+  }
+  return guest
+}
+
+ipcMain.handle('openDevTools', (event, webContentsId) => {
+  const guest = getGuestForWebContents(webContentsId, event.sender)
+  guest.openDevTools()
+})
+
+// renderer
+const { ipcRenderer } = require('electron')
+
+ipcRenderer.invoke('openDevTools', webview.getWebContentsId())
+```
+
+### `webFrame.setLayoutZoomLevelLimits()`
+
+Chromium has removed support for changing the layout zoom level limits, and it
+is beyond Electron's capacity to maintain it. The function will emit a warning
+in Electron 8.x, and cease to exist in Electron 9.x. The layout zoom level
+limits are now fixed at a minimum of 0.25 and a maximum of 5.0, as defined
+[here](https://chromium.googlesource.com/chromium/src/+/938b37a6d2886bf8335fc7db792f1eb46c65b2ae/third_party/blink/common/page/page_zoom.cc#11).
+
 ## Planned Breaking API Changes (7.0)

 ### Node Headers URL
@@ -50,7 +190,7 @@ const idleTime = getSystemIdleTime()
 ### webFrame Isolated World APIs

 ```js
-// Removed in Elecron 7.0
+// Removed in Electron 7.0
 webFrame.setIsolatedWorldContentSecurityPolicy(worldId, csp)
 webFrame.setIsolatedWorldHumanReadableName(worldId, name)
 webFrame.setIsolatedWorldSecurityOrigin(worldId, securityOrigin)
@@ -68,6 +208,39 @@ webFrame.setIsolatedWorldInfo(

 This property was removed in Chromium 77, and as such is no longer available.

+### `webkitdirectory` attribute for `<input type="file"/>`
+
+The `webkitdirectory` property on HTML file inputs allows them to select folders.
+Previous versions of Electron had an incorrect implementation where the `event.target.files`
+of the input returned a `FileList` that returned one `File` corresponding to the selected folder.
+
+As of Electron 7, that `FileList` is now list of all files contained within
+the folder, similarly to Chrome, Firefox, and Edge
+([link to MDN docs](https://developer.mozilla.org/en-US/docs/Web/API/HTMLInputElement/webkitdirectory)).
+
+As an illustration, take a folder with this structure:
+```console
+folder
+├── file1
+├── file2
+└── file3
+```
+
+In Electron <=6, this would return a `FileList` with a `File` object for:
+```console
+path/to/folder
+```
+
+In Electron 7, this now returns a `FileList` with a `File` object for:
+```console
+/path/to/folder/file3
+/path/to/folder/file2
+/path/to/folder/file1
+```
+
+Note that `webkitdirectory` no longer exposes the path to the selected folder.
+If you require the path to the selected folder rather than the folder contents,
+see the `dialog.showOpenDialog` API ([link](https://github.com/electron/electron/blob/master/docs/api/dialog.md#dialogshowopendialogbrowserwindow-options)).
 ## Planned Breaking API Changes (6.0)

 ### `win.setMenu(null)`
--- a/docs/development/README.md
+++ b/docs/development/README.md
@@ -22,6 +22,5 @@ For guides on Electron app development, see
 * [Debugging on Windows](debug-instructions-windows.md)
 * [Debugging on macOS](debugging-instructions-macos.md)
 * [Setting Up Symbol Server in Debugger](setting-up-symbol-server.md)
-* [Upgrading Chromium](upgrading-chromium.md)
-* [Upgrading Crashpad](upgrading-crashpad.md)
+* [Patches](patches.md)
 * [Upgrading Node](upgrading-node.md)
--- a/docs/development/build-instructions-gn.md
+++ b/docs/development/build-instructions-gn.md
@@ -46,7 +46,7 @@ You can avoid much of the wait by reusing Electron CI's build output via
 optional steps (listed below) and these two environment variables:

 ```sh
-export SCCACHE_BUCKET="electronjs-sccache"
+export SCCACHE_BUCKET="electronjs-sccache-ci"
 export SCCACHE_TWO_TIER=true
 ```

@@ -72,6 +72,7 @@ origin URLs.
 $ cd src/electron
 $ git remote remove origin
 $ git remote add origin https://github.com/electron/electron
+$ git checkout master
 $ git branch --set-upstream-to=origin/master
 $ cd -
 ```
@@ -95,30 +96,30 @@ $ cd src
 $ export CHROMIUM_BUILDTOOLS_PATH=`pwd`/buildtools
 # this next line is needed only if building with sccache
 $ export GN_EXTRA_ARGS="${GN_EXTRA_ARGS} cc_wrapper=\"${PWD}/electron/external_binaries/sccache\""
-$ gn gen out/Debug --args="import(\"//electron/build/args/debug.gn\") $GN_EXTRA_ARGS"
+$ gn gen out/Testing --args="import(\"//electron/build/args/testing.gn\") $GN_EXTRA_ARGS"
 ```

 Or on Windows (without the optional argument):
 ```sh
 $ cd src
 $ set CHROMIUM_BUILDTOOLS_PATH=%cd%\buildtools
-$ gn gen out/Debug --args="import(\"//electron/build/args/debug.gn\")"
+$ gn gen out/Testing --args="import(\"//electron/build/args/testing.gn\")"
 ```

-This will generate a build directory `out/Debug` under `src/` with
-debug build configuration. You can replace `Debug` with another name,
+This will generate a build directory `out/Testing` under `src/` with
+the testing build configuration. You can replace `Testing` with another name,
 but it should be a subdirectory of `out`.
 Also you shouldn't have to run `gn gen` again—if you want to change the
-build arguments, you can run `gn args out/Debug` to bring up an editor.
+build arguments, you can run `gn args out/Testing` to bring up an editor.

 To see the list of available build configuration options, run `gn args
-out/Debug --list`.
+out/Testing --list`.

-**For generating Debug (aka "component" or "shared") build config of
+**For generating Testing build config of
 Electron:**

 ```sh
-$ gn gen out/Debug --args="import(\"//electron/build/args/debug.gn\") $GN_EXTRA_ARGS"
+$ gn gen out/Testing --args="import(\"//electron/build/args/testing.gn\") $GN_EXTRA_ARGS"
 ```

 **For generating Release (aka "non-component" or "static") build config of
@@ -131,9 +132,9 @@ $ gn gen out/Release --args="import(\"//electron/build/args/release.gn\") $GN_EX
 **To build, run `ninja` with the `electron` target:**
 Nota Bene: This will also take a while and probably heat up your lap.

-For the debug configuration:
+For the testing configuration:
 ```sh
-$ ninja -C out/Debug electron
+$ ninja -C out/Testing electron
 ```

 For the release configuration:
@@ -146,19 +147,19 @@ This will build all of what was previously 'libchromiumcontent' (i.e. the
 so it will take a while.

 To speed up subsequent builds, you can use [sccache][sccache]. Add the GN arg
-`cc_wrapper = "sccache"` by running `gn args out/Debug` to bring up an
+`cc_wrapper = "sccache"` by running `gn args out/Testing` to bring up an
 editor and adding a line to the end of the file.

 [sccache]: https://github.com/mozilla/sccache

-The built executable will be under `./out/Debug`:
+The built executable will be under `./out/Testing`:

 ```sh
-$ ./out/Debug/Electron.app/Contents/MacOS/Electron
+$ ./out/Testing/Electron.app/Contents/MacOS/Electron
 # or, on Windows
-$ ./out/Debug/electron.exe
+$ ./out/Testing/electron.exe
 # or, on Linux
-$ ./out/Debug/electron
+$ ./out/Testing/electron
 ```

 ### Packaging
@@ -180,7 +181,7 @@ set the `target_cpu` and `target_os` GN arguments. For example, to compile an
 x86 target from an x64 host, specify `target_cpu = "x86"` in `gn args`.

 ```sh
-$ gn gen out/Debug-x86 --args='... target_cpu = "x86"'
+$ gn gen out/Testing-x86 --args='... target_cpu = "x86"'
 ```

 Not all combinations of source and target CPU/OS are supported by Chromium.
@@ -225,28 +226,17 @@ generate build headers for the modules to compile against, run the following
 under `src/` directory.

 ```sh
-$ ninja -C out/Debug third_party/electron_node:headers
-# Install the test modules with the generated headers
-$ (cd electron/spec && npm i --nodedir=../../out/Debug/gen/node_headers)
+$ ninja -C out/Testing third_party/electron_node:headers
 ```

-Then, run Electron with `electron/spec` as the argument:
-
-```sh
-# on Mac:
-$ ./out/Debug/Electron.app/Contents/MacOS/Electron electron/spec
-# on Windows:
-$ ./out/Debug/electron.exe electron/spec
-# on Linux:
-$ ./out/Debug/electron electron/spec
-```
+You can now [run the tests](testing.md#unit-tests).

 If you're debugging something, it can be helpful to pass some extra flags to
 the Electron binary:

 ```sh
-$ ./out/Debug/Electron.app/Contents/MacOS/Electron electron/spec \
-  --ci --enable-logging -g 'BrowserWindow module'
+$ npm run test -- \
+  --enable-logging -g 'BrowserWindow module'
 ```

 ## Sharing the git cache between multiple machines
@@ -275,8 +265,7 @@ New-ItemProperty -Path "HKLM:\System\CurrentControlSet\Services\Lanmanworkstatio

 ### Stale locks in the git cache
 If `gclient sync` is interrupted while using the git cache, it will leave
-the cache locked. To remove the lock, pass the `--break_repo_locks` argument to
-`gclient sync`.
+the cache locked. To remove the lock, pass the `--ignore_locks` argument to `gclient sync`.

 ### I'm being asked for a username/password for chromium-internal.googlesource.com
 If you see a prompt for `Username for 'https://chrome-internal.googlesource.com':` when running `gclient sync` on Windows, it's probably because the `DEPOT_TOOLS_WIN_TOOLCHAIN` environment variable is not set to 0. Open `Control Panel` → `System and Security` → `System` → `Advanced system settings` and add a system variable
--- a/docs/development/build-instructions-linux.md
+++ b/docs/development/build-instructions-linux.md
@@ -79,7 +79,7 @@ And to cross-compile for `arm` or `ia32` targets, you should pass the
 `target_cpu` parameter to `gn gen`:

 ```sh
-$ gn gen out/Debug --args='import(...) target_cpu="arm"'
+$ gn gen out/Testing --args='import(...) target_cpu="arm"'
 ```

 ## Building
@@ -114,7 +114,7 @@ GN args.
 For example if you installed `clang` under `/usr/local/bin/clang`:

 ```sh
-$ gn gen out/Debug --args='import("//electron/build/args/debug.gn") clang_base_path = "/usr/local/bin"'
+$ gn gen out/Testing --args='import("//electron/build/args/testing.gn") clang_base_path = "/usr/local/bin"'
 ```

 ### Using compilers other than `clang`
--- a/docs/development/build-instructions-windows.md
+++ b/docs/development/build-instructions-windows.md
@@ -11,9 +11,8 @@ Follow the guidelines below for building Electron on Windows.
  components are required.
  * If your Visual Studio is installed in a directory other than the default, you'll need to
  set a few environment variables to point the toolchains to your installation path.
-    * `vs2019_install = DRIVE:\path\to\Microsoft Visual Studio\2019\Community`
-       (replace `2019` and `Community` with your installed versions)
-    * `WINDOWSSDKDIR = DRIVE:\path\to\Windows Kits\10`
+    * `vs2019_install = DRIVE:\path\to\Microsoft Visual Studio\2019\Community`, replacing `2019` and `Community` with your installed versions and replacing `DRIVE:` with the drive that Visual Studio is on. Often, this will be `C:`.
+    * `WINDOWSSDKDIR = DRIVE:\path\to\Windows Kits\10`, replacing `DRIVE:` with the drive that Windows Kits is on. Often, this will be `C:`.
 * [Python 2.7.10 or higher](http://www.python.org/download/releases/2.7/)
  * Contrary to the `depot_tools` setup instructions linked below, you will need
  to use your locally installed Python with at least version 2.7.10 (with
@@ -74,7 +73,7 @@ To generate a Visual Studio project, you can pass the `--ide=vs2017` parameter
 to `gn gen`:

 ```powershell
-$ gn gen out/Debug --ide=vs2017
+$ gn gen out/Testing --ide=vs2017
 ```

 ## Troubleshooting
--- a/docs/development/build-system-overview.md
+++ b/docs/development/build-system-overview.md
@@ -57,7 +57,7 @@ you're currently working on using Mocha's
 `.only` to any `describe` or `it` function call:

 ```js
-describe.only('some feature', function () {
+describe.only('some feature', () => {
  // ... only tests in this block will be run
 })
 ```
--- a/docs/development/coding-style.md
+++ b/docs/development/coding-style.md
@@ -54,7 +54,7 @@ formatted correctly.
  the `module-name` form. This rule only applies to `.js` files.
 * Use newer ES6/ES2015 syntax where appropriate
  * [`const`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/const)
-    for requires and other constants
+    for requires and other constants.  If the value is a primitive, use uppercase naming (eg `const NUMBER_OF_RETRIES = 5`).
  * [`let`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/let)
    for defining variables
  * [Arrow functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/Arrow_functions)
--- a/docs/development/debug-instructions-windows.md
+++ b/docs/development/debug-instructions-windows.md
@@ -36,7 +36,7 @@ To start a debugging session, open up PowerShell/CMD and execute your debug
 build of Electron, using the application to open as a parameter.

 ```powershell
-$ ./out/Debug/electron.exe ~/my-electron-app/
+$ ./out/Testing/electron.exe ~/my-electron-app/
 ```

 ### Setting Breakpoints
--- a/docs/development/debugging-instructions-macos-xcode.md
+++ b/docs/development/debugging-instructions-macos-xcode.md
@@ -3,7 +3,7 @@
 ### Generate xcode project for debugging sources (cannot build code from xcode)
 Run `gn gen` with the --ide=xcode argument.
 ```sh
-$ gn gen out/Debug --ide=xcode
+$ gn gen out/Testing --ide=xcode
 ```
 This will generate the electron.ninja.xcworkspace. You will have to open this workspace
 to set breakpoints and inspect.
--- a/Show More
+++ b/Show More