fix: use uppercase trace event phases for perfetto compatibility

Node.js's trace_events_async_hooks.js uses lowercase phase characters
('b'/'e' for NESTABLE_ASYNC_BEGIN/END) when calling V8's trace builtin.
In perfetto mode, V8's builtins-trace.cc only handles uppercase phases
('B'/'E'/'I'), causing a "Trace event phase must be a number" TypeError
that breaks utility process startup when contentTracing is active.

This was already fixed for lib/internal/http.js in the existing
build_enable_perfetto patch but trace_events_async_hooks.js was missed.

Also fixes the --trace-startup spec by removing embedded quotes from
the glob pattern argument that triggered a PERFETTO_CHECK assertion in
perfetto's NameMatchesPattern.

.remarkrc

@@ -1,6 +0,0 @@
-{
-  "plugins": [
-    ["remark-lint-code-block-style", "fenced"],
-    ["remark-lint-fenced-code-flag"]
-  ]
-}

build/args/all.gn

@@ -2,7 +2,7 @@ is_electron_build = true
 root_extra_deps = [ "//electron" ]
 
 # Registry of NMVs --> https://github.com/nodejs/node/blob/main/doc/abi_version_registry.json
-node_module_version = 145
+node_module_version = 146
 
 v8_promise_internal_field_count = 1
 v8_embedder_string = "-electron.0"

chromium_src/BUILD.gn

@@ -245,6 +245,10 @@ static_library("chrome") {
       "//chrome/browser/ui/views/dark_mode_manager_linux.cc",
       "//chrome/browser/ui/views/dark_mode_manager_linux.h",
     ]
+    sources += [
+      "//chrome/browser/ui/views/frame/browser_frame_view_paint_utils_linux.cc",
+      "//chrome/browser/ui/views/frame/browser_frame_view_paint_utils_linux.h",
+    ]
     public_deps += [ "//components/dbus" ]
   }
 

docs/development/coding-style.md

@@ -39,7 +39,7 @@ etc.
 
 ## Documentation
 
-* Write [remark](https://github.com/remarkjs/remark) markdown style.
+* Write prose according to our [documentation style guide](./style-guide.md).
 
 You can run `npm run lint:docs` to ensure that your documentation changes are
 formatted correctly.

package.json

@@ -45,8 +45,6 @@
     "null-loader": "^4.0.1",
     "pre-flight": "^2.0.0",
     "process": "^0.11.10",
-    "remark-cli": "^12.0.1",
-    "remark-preset-lint-markdown-style-guide": "^6.0.1",
     "semver": "^7.6.3",
     "stream-json": "^1.9.1",
     "tap-xunit": "^2.4.1",
@@ -73,7 +71,7 @@
     "lint:objc": "node ./script/lint.js --objc",
     "lint:py": "node ./script/lint.js --py",
     "lint:gn": "node ./script/lint.js --gn",
-    "lint:docs": "remark docs -qf && npm run lint:js-in-markdown && npm run create-typescript-definitions && npm run lint:ts-check-js-in-markdown && npm run lint:docs-fiddles && npm run lint:docs-relative-links && npm run lint:markdown && npm run lint:api-history",
+    "lint:docs": "npm run lint:js-in-markdown && npm run create-typescript-definitions && npm run lint:ts-check-js-in-markdown && npm run lint:docs-fiddles && npm run lint:docs-relative-links && npm run lint:markdown && npm run lint:api-history",
     "lint:docs-fiddles": "standard \"docs/fiddles/**/*.js\"",
     "lint:docs-relative-links": "lint-roller-markdown-links --resource-root . --root docs \"**/*.md\"",
     "lint:markdown": "node ./script/lint.js --md",

patches/chromium/chore_add_electron_objects_to_wrappablepointertag.patch

@@ -8,10 +8,10 @@ electron objects that extend gin::Wrappable and gets
 allocated on the cpp heap
 
 diff --git a/gin/public/wrappable_pointer_tags.h b/gin/public/wrappable_pointer_tags.h
-index c29e8554933994ff56ccea394af34e17c4e9fc2c..42512541b36ceb353483a29eca2c858b9628854b 100644
+index c29e8554933994ff56ccea394af34e17c4e9fc2c..6befb717f83d93d97033c240aa281e0bcb94e69c 100644
 --- a/gin/public/wrappable_pointer_tags.h
 +++ b/gin/public/wrappable_pointer_tags.h
-@@ -76,7 +76,19 @@ enum WrappablePointerTag : uint16_t {
+@@ -76,7 +76,20 @@ enum WrappablePointerTag : uint16_t {
    kTextInputControllerBindings,  // content::TextInputControllerBindings
    kWebAXObjectProxy,             // content::WebAXObjectProxy
    kWrappedExceptionHandler,      // extensions::WrappedExceptionHandler
@@ -27,6 +27,7 @@ index c29e8554933994ff56ccea394af34e17c4e9fc2c..42512541b36ceb353483a29eca2c858b
 +  kElectronReplyChannel,                // gin_helper::internal::ReplyChannel
 +  kElectronScreen,                      // electron::api::Screen
 +  kElectronSession,                     // electron::api::Session
++  kElectronTray,                        // electron::api::Tray
 +  kElectronWebRequest,                  // electron::api::WebRequest
 +  kLastPointerTag = kElectronWebRequest,
  };

patches/node/build_enable_perfetto.patch

@@ -63,6 +63,31 @@ index f8b4fd7c4ca5a0907806c7e804de8c951675a36a..209e3bcf8be5a23ac528dcd673bed82c
  }
  
  function ipToInt(ip) {
+diff --git a/lib/internal/trace_events_async_hooks.js b/lib/internal/trace_events_async_hooks.js
+index a9f517ffc9e4eea5bc68997ffadc85d43dde2a52..d3db6bf119a6bb9cea1d069957f89cc7f99512b7 100644
+--- a/lib/internal/trace_events_async_hooks.js
++++ b/lib/internal/trace_events_async_hooks.js
+@@ -11,15 +11,13 @@ const { trace } = internalBinding('trace_events');
+ const async_wrap = internalBinding('async_wrap');
+ const async_hooks = require('async_hooks');
+ const {
+-  CHAR_LOWERCASE_B,
+-  CHAR_LOWERCASE_E,
++  CHAR_UPPERCASE_B,
++  CHAR_UPPERCASE_E,
+ } = require('internal/constants');
+ 
+-// Use small letters such that chrome://tracing groups by the name.
+-// The behavior is not only useful but the same as the events emitted using
+-// the specific C++ macros.
+-const kBeforeEvent = CHAR_LOWERCASE_B;
+-const kEndEvent = CHAR_LOWERCASE_E;
++// See v8/src/builtins/builtins-trace.cc - must be uppercase for perfetto
++const kBeforeEvent = CHAR_UPPERCASE_B;
++const kEndEvent = CHAR_UPPERCASE_E;
+ const kTraceEventCategory = 'node,node.async_hooks';
+ 
+ const kEnabled = Symbol('enabled');
 diff --git a/node.gyp b/node.gyp
 index f5cd416b5fe7a51084bc4af9a4427a8e62599fd8..5eb70ce3820f2b82121bc102c5182ab768cbef36 100644
 --- a/node.gyp

patches/squirrel.mac/.patches

@@ -9,5 +9,5 @@ refactor_use_non-deprecated_nskeyedarchiver_apis.patch
 chore_turn_off_launchapplicationaturl_deprecation_errors_in_squirrel.patch
 fix_crash_when_process_to_extract_zip_cannot_be_launched.patch
 use_uttype_class_instead_of_deprecated_uttypeconformsto.patch
-fix_clean_up_old_staged_updates_before_downloading_new_update.patch
+fix_clean_up_orphaned_staged_updates_before_downloading_new_update.patch
 fix_add_explicit_json_property_mappings_for_shipit_request_model.patch

patches/squirrel.mac/fix_clean_up_old_staged_updates_before_downloading_new_update.patch

@@ -1,64 +0,0 @@
-From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
-From: Andy Locascio <loc@anthropic.com>
-Date: Tue, 6 Jan 2026 08:23:03 -0800
-Subject: fix: clean up old staged updates before downloading new update
-
-When checkForUpdates() is called while an update is already staged,
-Squirrel creates a new temporary directory for the download without
-cleaning up the old one. This can lead to significant disk usage if
-the app keeps checking for updates without restarting.
-
-This change adds a force parameter to pruneUpdateDirectories that
-bypasses the AwaitingRelaunch state check. This is called before
-creating a new temp directory, ensuring old staged updates are
-cleaned up when a new download starts.
-
-diff --git a/Squirrel/SQRLUpdater.m b/Squirrel/SQRLUpdater.m
-index d156616e81e6f25a3bded30e6216b8fc311f31bc..6cd4346bf43b191147aff819cb93387e71275a46 100644
---- a/Squirrel/SQRLUpdater.m
-+++ b/Squirrel/SQRLUpdater.m
-@@ -543,11 +543,17 @@ - (RACSignal *)downloadBundleForUpdate:(SQRLUpdate *)update intoDirectory:(NSURL
- #pragma mark File Management
- 
- - (RACSignal *)uniqueTemporaryDirectoryForUpdate {
--	return [[[RACSignal
-+	// Clean up any old staged update directories before creating a new one.
-+	// This prevents disk usage from growing when checkForUpdates() is called
-+	// multiple times without the app restarting.
-+	return [[[[[self
-+		pruneUpdateDirectoriesWithForce:YES]
-+		ignoreValues]
-+		concat:[RACSignal
- 		defer:^{
- 			SQRLDirectoryManager *directoryManager = [[SQRLDirectoryManager alloc] initWithApplicationIdentifier:SQRLShipItLauncher.shipItJobLabel];
- 			return [directoryManager storageURL];
--		}]
-+		}]]
- 		flattenMap:^(NSURL *storageURL) {
- 			NSURL *updateDirectoryTemplate = [storageURL URLByAppendingPathComponent:[SQRLUpdaterUniqueTemporaryDirectoryPrefix stringByAppendingString:@"XXXXXXX"]];
- 			char *updateDirectoryCString = strdup(updateDirectoryTemplate.path.fileSystemRepresentation);
-@@ -643,7 +649,7 @@ - (BOOL)isRunningOnReadOnlyVolume {
- 
- - (RACSignal *)performHousekeeping {
- 	return [[RACSignal
--		merge:@[ [self pruneUpdateDirectories], [self truncateLogs] ]]
-+		merge:@[ [self pruneUpdateDirectoriesWithForce:NO], [self truncateLogs] ]]
- 		catch:^(NSError *error) {
- 			NSLog(@"Error doing housekeeping: %@", error);
- 			return [RACSignal empty];
-@@ -658,11 +664,12 @@ - (RACSignal *)performHousekeeping {
- ///
- /// Sends each removed directory then completes, or errors, on an unspecified
- /// thread.
--- (RACSignal *)pruneUpdateDirectories {
-+- (RACSignal *)pruneUpdateDirectoriesWithForce:(BOOL)force {
- 	return [[[RACSignal
- 		defer:^{
--			// If we already have updates downloaded we don't wanna prune them.
--			if (self.state == SQRLUpdaterStateAwaitingRelaunch) return [RACSignal empty];
-+			// If we already have updates downloaded we don't wanna prune them,
-+			// unless force is YES (used when starting a new download).
-+			if (!force && self.state == SQRLUpdaterStateAwaitingRelaunch) return [RACSignal empty];
- 
- 			SQRLDirectoryManager *directoryManager = [[SQRLDirectoryManager alloc] initWithApplicationIdentifier:SQRLShipItLauncher.shipItJobLabel];
- 			return [directoryManager storageURL];

patches/squirrel.mac/fix_clean_up_orphaned_staged_updates_before_downloading_new_update.patch

@@ -0,0 +1,130 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Andy Locascio <loc@anthropic.com>
+Date: Tue, 6 Jan 2026 08:23:03 -0800
+Subject: fix: clean up orphaned staged updates before downloading new update
+
+When checkForUpdates() is called while an update is already staged,
+Squirrel creates a new temporary directory for the download without
+cleaning up the old one. This can lead to significant disk usage if
+the app keeps checking for updates without restarting.
+
+This change adds a pruneOrphanedUpdateDirectories step before creating
+a new temp directory. Unlike a blanket prune, this reads the current
+ShipItState.plist and preserves the directory it references, deleting
+only truly orphaned update directories. This keeps the on-disk
+footprint bounded (at most 2 dirs) while ensuring quitAndInstall
+remains safe to call even when a new check is in progress.
+
+Refs https://github.com/electron/electron/issues/50200
+
+diff --git a/Squirrel/SQRLUpdater.m b/Squirrel/SQRLUpdater.m
+index d156616e81e6f25a3bded30e6216b8fc311f31bc..41856e5754228d33982db72f97f2ff241615a357 100644
+--- a/Squirrel/SQRLUpdater.m
++++ b/Squirrel/SQRLUpdater.m
+@@ -543,11 +543,19 @@ - (RACSignal *)downloadBundleForUpdate:(SQRLUpdate *)update intoDirectory:(NSURL
+ #pragma mark File Management
+ 
+ - (RACSignal *)uniqueTemporaryDirectoryForUpdate {
+-	return [[[RACSignal
++	// Clean up any orphaned update directories before creating a new one.
++	// This prevents disk usage from growing when checkForUpdates() is called
++	// multiple times without the app restarting. The currently staged update
++	// (referenced by ShipItState.plist) is always preserved so quitAndInstall
++	// remains safe to call while a new check is in progress.
++	return [[[[[self
++		pruneOrphanedUpdateDirectories]
++		ignoreValues]
++		concat:[RACSignal
+ 		defer:^{
+ 			SQRLDirectoryManager *directoryManager = [[SQRLDirectoryManager alloc] initWithApplicationIdentifier:SQRLShipItLauncher.shipItJobLabel];
+ 			return [directoryManager storageURL];
+-		}]
++		}]]
+ 		flattenMap:^(NSURL *storageURL) {
+ 			NSURL *updateDirectoryTemplate = [storageURL URLByAppendingPathComponent:[SQRLUpdaterUniqueTemporaryDirectoryPrefix stringByAppendingString:@"XXXXXXX"]];
+ 			char *updateDirectoryCString = strdup(updateDirectoryTemplate.path.fileSystemRepresentation);
+@@ -668,25 +676,68 @@ - (RACSignal *)pruneUpdateDirectories {
+ 			return [directoryManager storageURL];
+ 		}]
+ 		flattenMap:^(NSURL *storageURL) {
+-			NSFileManager *manager = [[NSFileManager alloc] init];
+-			NSDirectoryEnumerator *enumerator = [manager enumeratorAtURL:storageURL includingPropertiesForKeys:nil options:NSDirectoryEnumerationSkipsSubdirectoryDescendants errorHandler:^(NSURL *URL, NSError *error) {
+-				NSLog(@"Error enumerating item %@ within directory %@: %@", URL, storageURL, error);
+-				return YES;
+-			}];
++			return [self removeUpdateDirectoriesInStorageURL:storageURL excludingURL:nil];
++		}]
++		setNameWithFormat:@"%@ -prunedUpdateDirectories", self];
++}
+ 
+-			return [[enumerator.rac_sequence.signal
+-				filter:^(NSURL *enumeratedURL) {
+-					NSString *name = enumeratedURL.lastPathComponent;
+-					return [name hasPrefix:SQRLUpdaterUniqueTemporaryDirectoryPrefix];
+-				}]
+-				doNext:^(NSURL *directoryURL) {
+-					NSError *error = nil;
+-					if (![manager removeItemAtURL:directoryURL error:&error]) {
+-						NSLog(@"Error removing old update directory at %@: %@", directoryURL, error.sqrl_verboseDescription);
+-					}
++/// Lazily removes orphaned temporary directories upon subscription, always
++/// preserving the directory currently referenced by ShipItState.plist so that
++/// quitAndInstall remains safe to call mid-check.
++///
++/// Safe to call in any state. Sends each removed directory then completes on
++/// an unspecified thread. Errors reading the staged request are swallowed
++/// (treated as "nothing staged").
++- (RACSignal *)pruneOrphanedUpdateDirectories {
++	return [[[[[SQRLShipItRequest
++		readUsingURL:self.shipItStateURL]
++		map:^(SQRLShipItRequest *request) {
++			// The request holds the URL to the staged .app bundle; its parent
++			// is the update.XXXXXXX directory we must preserve.
++			return [request.updateBundleURL URLByDeletingLastPathComponent];
++		}]
++		catch:^(NSError *error) {
++			// No staged request (or unreadable) — nothing to preserve.
++			return [RACSignal return:nil];
++		}]
++		flattenMap:^(NSURL *stagedDirectoryURL) {
++			SQRLDirectoryManager *directoryManager = [[SQRLDirectoryManager alloc] initWithApplicationIdentifier:SQRLShipItLauncher.shipItJobLabel];
++			return [[directoryManager storageURL]
++				flattenMap:^(NSURL *storageURL) {
++					return [self removeUpdateDirectoriesInStorageURL:storageURL excludingURL:stagedDirectoryURL];
+ 				}];
+ 		}]
+-		setNameWithFormat:@"%@ -prunedUpdateDirectories", self];
++		setNameWithFormat:@"%@ -pruneOrphanedUpdateDirectories", self];
++}
++
++/// Shared enumerate-and-delete logic for update temp directories.
++///
++/// storageURL  - The Squirrel storage root to enumerate. Must not be nil.
++/// excludedURL - Directory to skip (compared by standardized path). May be nil.
++- (RACSignal *)removeUpdateDirectoriesInStorageURL:(NSURL *)storageURL excludingURL:(NSURL *)excludedURL {
++	NSParameterAssert(storageURL != nil);
++
++	NSFileManager *manager = [[NSFileManager alloc] init];
++	NSDirectoryEnumerator *enumerator = [manager enumeratorAtURL:storageURL includingPropertiesForKeys:nil options:NSDirectoryEnumerationSkipsSubdirectoryDescendants errorHandler:^(NSURL *URL, NSError *error) {
++		NSLog(@"Error enumerating item %@ within directory %@: %@", URL, storageURL, error);
++		return YES;
++	}];
++
++	NSString *excludedPath = excludedURL.URLByStandardizingPath.path;
++
++	return [[enumerator.rac_sequence.signal
++		filter:^(NSURL *enumeratedURL) {
++			NSString *name = enumeratedURL.lastPathComponent;
++			if (![name hasPrefix:SQRLUpdaterUniqueTemporaryDirectoryPrefix]) return NO;
++			if (excludedPath != nil && [enumeratedURL.URLByStandardizingPath.path isEqualToString:excludedPath]) return NO;
++			return YES;
++		}]
++		doNext:^(NSURL *directoryURL) {
++			NSError *error = nil;
++			if (![manager removeItemAtURL:directoryURL error:&error]) {
++				NSLog(@"Error removing old update directory at %@: %@", directoryURL, error.sqrl_verboseDescription);
++			}
++		}];
+ }
+ 
+ 

shell/browser/api/electron_api_tray.cc

@@ -23,6 +23,8 @@
 #include "shell/common/gin_helper/error_thrower.h"
 #include "shell/common/gin_helper/handle.h"
 #include "shell/common/node_includes.h"
+#include "v8/include/cppgc/allocation.h"
+#include "v8/include/v8-cppgc.h"
 
 namespace gin {
 
@@ -48,12 +50,13 @@ struct Converter<electron::TrayIcon::IconType> {
 
 namespace electron::api {
 
-gin::DeprecatedWrapperInfo Tray::kWrapperInfo = {gin::kEmbedderNativeGin};
+const gin::WrapperInfo Tray::kWrapperInfo = {{gin::kEmbedderNativeGin},
+                                             gin::kElectronTray};
 
 Tray::Tray(v8::Isolate* isolate,
            v8::Local<v8::Value> image,
            std::optional<base::Uuid> guid)
-    : guid_(guid), tray_icon_(TrayIcon::Create(guid)) {
+    : guid_{guid}, tray_icon_{TrayIcon::Create(guid)} {
   SetImage(isolate, image);
   tray_icon_->AddObserver(this);
   if (guid.has_value())
@@ -63,10 +66,10 @@ Tray::Tray(v8::Isolate* isolate,
 Tray::~Tray() = default;
 
 // static
-gin_helper::Handle<Tray> Tray::New(gin_helper::ErrorThrower thrower,
-                                   v8::Local<v8::Value> image,
-                                   std::optional<base::Uuid> guid,
-                                   gin::Arguments* args) {
+Tray* Tray::New(gin_helper::ErrorThrower thrower,
+                v8::Local<v8::Value> image,
+                std::optional<base::Uuid> guid,
+                gin::Arguments* args) {
   if (!Browser::Get()->is_ready()) {
     thrower.ThrowError("Cannot create Tray before app is ready");
     return {};
@@ -80,17 +83,17 @@ gin_helper::Handle<Tray> Tray::New(gin_helper::ErrorThrower thrower,
   // Error thrown by us will be dropped when entering V8.
   // Make sure to abort early and propagate the error to JS.
   // Refs https://chromium-review.googlesource.com/c/v8/v8/+/5050065
-  v8::TryCatch try_catch(args->isolate());
-  auto* tray = new Tray(args->isolate(), image, guid);
+  v8::Isolate* isolate = args->isolate();
+  v8::TryCatch try_catch{isolate};
+  Tray* tray = cppgc::MakeGarbageCollected<Tray>(
+      isolate->GetCppHeap()->GetAllocationHandle(), isolate, image, guid);
   if (try_catch.HasCaught()) {
-    delete tray;
+    tray->keep_alive_.Clear();
     try_catch.ReThrow();
     return {};
   }
 
-  auto handle = gin_helper::CreateHandle(args->isolate(), tray);
-  handle->Pin(args->isolate());
-  return handle;
+  return tray;
 }
 
 void Tray::OnClicked(const gfx::Rect& bounds,
@@ -186,9 +189,9 @@ void Tray::OnDragEnded() {
 }
 
 void Tray::Destroy() {
-  Unpin();
-  menu_.Reset();
+  menu_.Clear();
   tray_icon_.reset();
+  keep_alive_.Clear();
 }
 
 bool Tray::IsDestroyed() {
@@ -374,12 +377,13 @@ void Tray::SetContextMenu(gin_helper::ErrorThrower thrower,
                           v8::Local<v8::Value> arg) {
   if (!CheckAlive())
     return;
-  gin_helper::Handle<Menu> menu;
+
   if (arg->IsNull()) {
-    menu_.Reset();
+    menu_.Clear();
     tray_icon_->SetContextMenu(nullptr);
-  } else if (gin::ConvertFromV8(thrower.isolate(), arg, &menu)) {
-    menu_.Reset(thrower.isolate(), menu.ToV8());
+  } else if (Menu* menu = nullptr;
+             gin::ConvertFromV8(thrower.isolate(), arg, &menu)) {
+    menu_ = menu;
     tray_icon_->SetContextMenu(menu->model());
   } else {
     thrower.ThrowTypeError("Must pass Menu or null");
@@ -437,12 +441,17 @@ void Tray::FillObjectTemplate(v8::Isolate* isolate,
       .Build();
 }
 
-const char* Tray::GetTypeName() {
-  return GetClassName();
+void Tray::Trace(cppgc::Visitor* visitor) const {
+  gin::Wrappable<Tray>::Trace(visitor);
+  visitor->Trace(menu_);
 }
 
-void Tray::WillBeDestroyed() {
-  ClearWeak();
+const gin::WrapperInfo* Tray::wrapper_info() const {
+  return &kWrapperInfo;
+}
+
+const char* Tray::GetHumanReadableName() const {
+  return "Electron / Tray";
 }
 
 }  // namespace electron::api
@@ -457,7 +466,7 @@ void Initialize(v8::Local<v8::Object> exports,
                 void* priv) {
   v8::Isolate* const isolate = electron::JavascriptEnvironment::GetIsolate();
   gin::Dictionary dict{isolate, exports};
-  dict.Set("Tray", Tray::GetConstructor(isolate, context));
+  dict.Set("Tray", Tray::GetConstructor(isolate, context, &Tray::kWrapperInfo));
 }
 
 }  // namespace

shell/browser/api/electron_api_tray.h

@@ -10,14 +10,13 @@
 #include <string>
 #include <vector>
 
+#include "gin/wrappable.h"
 #include "shell/browser/event_emitter_mixin.h"
 #include "shell/browser/ui/tray_icon.h"
 #include "shell/browser/ui/tray_icon_observer.h"
 #include "shell/common/gin_converters/guid_converter.h"
-#include "shell/common/gin_helper/cleaned_up_at_exit.h"
 #include "shell/common/gin_helper/constructible.h"
-#include "shell/common/gin_helper/pinnable.h"
-#include "shell/common/gin_helper/wrappable.h"
+#include "shell/common/gin_helper/self_keep_alive.h"
 
 namespace gfx {
 class Image;
@@ -27,47 +26,43 @@ class Image;
 namespace gin_helper {
 class Dictionary;
 class ErrorThrower;
-template <typename T>
-class Handle;
 }  // namespace gin_helper
 
 namespace electron::api {
 
 class Menu;
 
-class Tray final : public gin_helper::DeprecatedWrappable<Tray>,
+class Tray final : public gin::Wrappable<Tray>,
                    public gin_helper::EventEmitterMixin<Tray>,
                    public gin_helper::Constructible<Tray>,
-                   public gin_helper::CleanedUpAtExit,
-                   public gin_helper::Pinnable<Tray>,
                    private TrayIconObserver {
  public:
   // gin_helper::Constructible
-  static gin_helper::Handle<Tray> New(gin_helper::ErrorThrower thrower,
-                                      v8::Local<v8::Value> image,
-                                      std::optional<base::Uuid> guid,
-                                      gin::Arguments* args);
+  static Tray* New(gin_helper::ErrorThrower thrower,
+                   v8::Local<v8::Value> image,
+                   std::optional<base::Uuid> guid,
+                   gin::Arguments* args);
 
   static void FillObjectTemplate(v8::Isolate*, v8::Local<v8::ObjectTemplate>);
   static const char* GetClassName() { return "Tray"; }
 
-  // gin_helper::Wrappable
-  static gin::DeprecatedWrapperInfo kWrapperInfo;
-  const char* GetTypeName() override;
+  // gin::Wrappable
+  static const gin::WrapperInfo kWrapperInfo;
+  void Trace(cppgc::Visitor*) const override;
+  const gin::WrapperInfo* wrapper_info() const override;
+  const char* GetHumanReadableName() const override;
 
-  // gin_helper::CleanedUpAtExit
-  void WillBeDestroyed() override;
+  // Make public for cppgc::MakeGarbageCollected.
+  Tray(v8::Isolate* isolate,
+       v8::Local<v8::Value> image,
+       std::optional<base::Uuid> guid);
+  ~Tray() override;
 
   // disable copy
   Tray(const Tray&) = delete;
   Tray& operator=(const Tray&) = delete;
 
  private:
-  Tray(v8::Isolate* isolate,
-       v8::Local<v8::Value> image,
-       std::optional<base::Uuid> guid);
-  ~Tray() override;
-
   // TrayIconObserver:
   void OnClicked(const gfx::Rect& bounds,
                  const gfx::Point& location,
@@ -115,9 +110,10 @@ class Tray final : public gin_helper::DeprecatedWrappable<Tray>,
 
   bool CheckAlive();
 
-  v8::Global<v8::Value> menu_;
+  cppgc::Member<Menu> menu_;
   std::optional<base::Uuid> guid_;
   std::unique_ptr<TrayIcon> tray_icon_;
+  gin_helper::SelfKeepAlive<Tray> keep_alive_{this};
 };
 
 }  // namespace electron::api

shell/browser/native_window_mac.h

@@ -172,6 +172,12 @@ class NativeWindowMac : public NativeWindow,
   void NotifyWindowDidFailToEnterFullScreen();
   void NotifyWindowWillLeaveFullScreen();
 
+  // Hide/show traffic light buttons around miniaturize/deminiaturize to
+  // prevent them from flashing at the default position during the restore
+  // animation when a custom trafficLightPosition is configured.
+  void HideTrafficLights();
+  void RestoreTrafficLights();
+
   // Cleanup observers when window is getting closed. Note that the destructor
   // can be called much later after window gets closed, so we should not do
   // cleanup in destructor.

shell/browser/native_window_mac.mm

@@ -1535,6 +1535,18 @@ void NativeWindowMac::RedrawTrafficLights() {
     [buttons_proxy_ redraw];
 }
 
+void NativeWindowMac::HideTrafficLights() {
+  if (buttons_proxy_)
+    [buttons_proxy_ setVisible:NO];
+}
+
+void NativeWindowMac::RestoreTrafficLights() {
+  if (buttons_proxy_ && window_button_visibility_.value_or(true)) {
+    [buttons_proxy_ redraw];
+    [buttons_proxy_ setVisible:YES];
+  }
+}
+
 // In simpleFullScreen mode, update the frame for new bounds.
 void NativeWindowMac::UpdateFrame() {
   NSWindow* window = GetNativeWindow().GetNativeNSWindow();

shell/browser/ui/cocoa/electron_ns_window_delegate.mm

@@ -256,6 +256,10 @@ using TitleBarStyle = electron::NativeWindowMac::TitleBarStyle;
   shell_->SetWindowLevel(NSNormalWindowLevel);
   shell_->UpdateWindowOriginalFrame();
   shell_->DetachChildren();
+  // Hide the traffic light buttons container before miniaturize so that
+  // when the window is restored, macOS does not render the buttons at
+  // their default position during the deminiaturize animation.
+  shell_->HideTrafficLights();
 }
 
 - (void)windowDidMiniaturize:(NSNotification*)notification {
@@ -273,6 +277,10 @@ using TitleBarStyle = electron::NativeWindowMac::TitleBarStyle;
   shell_->set_wants_to_be_visible(true);
   shell_->AttachChildren();
   shell_->SetWindowLevel(level_);
+  // Reposition traffic light buttons and make them visible again.
+  // They were hidden in windowWillMiniaturize to prevent a flash at
+  // the default (0,0) position during the restore animation.
+  shell_->RestoreTrafficLights();
   shell_->NotifyWindowRestore();
 }
 

shell/browser/ui/electron_desktop_window_tree_host_linux.cc

@@ -243,8 +243,8 @@ void ElectronDesktopWindowTreeHostLinux::UpdateFrameHints() {
         // The opaque region is a list of rectangles that contain only fully
         // opaque pixels of the window.  We need to convert the clipping
         // rounded-rect into this format.
-        SkRRect rrect = layout->GetRoundedWindowContentBounds();
-        gfx::RectF rectf(layout->GetWindowContentBounds());
+        SkRRect rrect = layout->GetRoundedWindowBounds();
+        gfx::RectF rectf(layout->GetWindowBounds());
         rectf.Scale(scale);
         // It is acceptable to omit some pixels that are opaque, but the region
         // must not include any translucent pixels.  Therefore, we must

shell/browser/ui/views/client_frame_view_linux.cc

@@ -112,7 +112,7 @@ ClientFrameViewLinux::~ClientFrameViewLinux() {
 void ClientFrameViewLinux::Init(NativeWindowViews* window,
                                 views::Widget* frame) {
   FramelessView::Init(window, frame);
-  linux_frame_layout_ = std::make_unique<LinuxCSDFrameLayout>(window);
+  linux_frame_layout_ = std::make_unique<LinuxCSDNativeFrameLayout>(window);
 
   // Unretained() is safe because the subscription is saved into an instance
   // member and thus will be cancelled upon the instance's destruction.
@@ -156,7 +156,8 @@ void ClientFrameViewLinux::OnWindowButtonOrderingChange() {
 }
 
 int ClientFrameViewLinux::ResizingBorderHitTest(const gfx::Point& point) {
-  return ResizingBorderHitTestImpl(point, RestoredFrameBorderInsets());
+  return ResizingBorderHitTestImpl(
+      point, linux_frame_layout_->GetResizeBorderInsets());
 }
 
 gfx::Rect ClientFrameViewLinux::GetBoundsForClientView() const {
@@ -235,8 +236,11 @@ void ClientFrameViewLinux::Layout(PassKey) {
 }
 
 void ClientFrameViewLinux::OnPaint(gfx::Canvas* canvas) {
-  linux_frame_layout_->PaintWindowFrame(
-      canvas, GetLocalBounds(), GetTitlebarBounds(), ShouldPaintAsActive());
+  if (auto* frame_provider = linux_frame_layout_->GetFrameProvider()) {
+    frame_provider->PaintWindowFrame(
+        canvas, GetLocalBounds(), GetTitlebarBounds().bottom(),
+        ShouldPaintAsActive(), linux_frame_layout_->GetInputInsets());
+  }
 }
 
 void ClientFrameViewLinux::PaintAsActiveChanged() {
@@ -267,7 +271,7 @@ void ClientFrameViewLinux::UpdateThemeValues() {
   }
 
   theme_values_.window_border_radius =
-      linux_frame_layout_->GetFrameProvider()->GetTopCornerRadiusDip();
+      linux_frame_layout_->GetTopCornerRadiusDip();
 
   gtk::GtkStyleContextGet(headerbar_context, "min-height",
                           &theme_values_.titlebar_min_height, nullptr);

shell/browser/ui/views/client_frame_view_linux.h

@@ -112,7 +112,7 @@ class ClientFrameViewLinux : public FramelessView,
   gfx::Insets GetTitlebarContentInsets() const;
   gfx::Rect GetTitlebarContentBounds() const;
 
-  std::unique_ptr<LinuxFrameLayout> linux_frame_layout_;
+  std::unique_ptr<LinuxCSDNativeFrameLayout> linux_frame_layout_;
 
   raw_ptr<ui::NativeTheme> theme_;
   ThemeValues theme_values_;

shell/browser/ui/views/linux_frame_layout.cc

@@ -4,14 +4,20 @@
 // found in the LICENSE file.
 
 #include "shell/browser/ui/views/linux_frame_layout.h"
+
+#include <algorithm>
+
 #include "base/i18n/rtl.h"
+#include "chrome/browser/ui/views/frame/browser_frame_view_paint_utils_linux.h"  // nogncheck
+#include "shell/browser/linux/x11_util.h"
 #include "shell/browser/native_window_views.h"
 #include "shell/browser/ui/electron_desktop_window_tree_host_linux.h"
-#include "ui/gfx/canvas.h"
+#include "third_party/skia/include/core/SkRRect.h"
 #include "ui/gfx/geometry/insets.h"
 #include "ui/gfx/geometry/skia_conversions.h"
 #include "ui/linux/linux_ui.h"
-#include "ui/native_theme/native_theme.h"
+#include "ui/linux/window_frame_provider.h"
+#include "ui/views/layout/layout_provider.h"
 #include "ui/views/widget/widget.h"
 
 namespace electron {
@@ -21,151 +27,174 @@ namespace {
 constexpr int kResizeBorder = 10;
 // This should match FramelessView's inside resize band.
 constexpr int kResizeInsideBoundsSize = 5;
+// These should match Chromium's restored frame edge thickness.
+constexpr gfx::Insets kDefaultCustomFrameBorder = gfx::Insets::TLBR(2, 1, 1, 1);
+
+bool CheckClientFrameShadowSupport(NativeWindowViews* window) {
+  auto* tree_host = static_cast<ElectronDesktopWindowTreeHostLinux*>(
+      ElectronDesktopWindowTreeHostLinux::GetHostForWidget(
+          window->GetAcceleratedWidget()));
+  return tree_host && tree_host->SupportsClientFrameShadow();
+}
 }  // namespace
 
 // static
 std::unique_ptr<LinuxFrameLayout> LinuxFrameLayout::Create(
     NativeWindowViews* window,
-    bool wants_shadow) {
+    bool wants_shadow,
+    CSDStyle csd_style) {
   if (x11_util::IsX11() || window->IsTranslucent() || !wants_shadow) {
-    return std::make_unique<LinuxUndecoratedFrameLayout>(window);
+    return std::make_unique<LinuxFrameLayout>(window);
+  } else if (csd_style == CSDStyle::kCustom) {
+    return std::make_unique<LinuxCSDCustomFrameLayout>(window);
   } else {
-    return std::make_unique<LinuxCSDFrameLayout>(window);
+    return std::make_unique<LinuxCSDNativeFrameLayout>(window);
   }
 }
 
-LinuxCSDFrameLayout::LinuxCSDFrameLayout(NativeWindowViews* window)
-    : window_(window) {
-  host_supports_client_frame_shadow_ = SupportsClientFrameShadow();
+gfx::Insets LinuxFrameLayout::GetResizeBorderInsets() const {
+  gfx::Insets insets = RestoredFrameBorderInsets();
+  return insets.IsEmpty() ? GetInputInsets() : insets;
 }
 
-bool LinuxCSDFrameLayout::tiled() const {
-  return tiled_;
-}
-
-void LinuxCSDFrameLayout::set_tiled(bool tiled) {
-  tiled_ = tiled;
-}
-
-gfx::Insets LinuxCSDFrameLayout::RestoredFrameBorderInsets() const {
-  gfx::Insets insets = GetFrameProvider()->GetFrameThicknessDip();
-  const gfx::Insets input = GetInputInsets();
-
-  auto expand_if_visible = [](int side_thickness, int min_band) {
-    return side_thickness > 0 ? std::max(side_thickness, min_band) : 0;
-  };
-
-  gfx::Insets merged;
-  merged.set_top(expand_if_visible(insets.top(), input.top()));
-  merged.set_left(expand_if_visible(insets.left(), input.left()));
-  merged.set_bottom(expand_if_visible(insets.bottom(), input.bottom()));
-  merged.set_right(expand_if_visible(insets.right(), input.right()));
-
-  return base::i18n::IsRTL() ? gfx::Insets::TLBR(merged.top(), merged.right(),
-                                                 merged.bottom(), merged.left())
-                             : merged;
-}
-
-gfx::Insets LinuxCSDFrameLayout::GetInputInsets() const {
-  bool showing_shadow = host_supports_client_frame_shadow_ &&
-                        !window_->IsMaximized() && !window_->IsFullscreen();
-  return gfx::Insets(showing_shadow ? kResizeBorder : 0);
-}
-
-bool LinuxCSDFrameLayout::SupportsClientFrameShadow() const {
-  auto* tree_host = static_cast<ElectronDesktopWindowTreeHostLinux*>(
-      ElectronDesktopWindowTreeHostLinux::GetHostForWidget(
-          window_->GetAcceleratedWidget()));
-  return tree_host->SupportsClientFrameShadow();
-}
-
-void LinuxCSDFrameLayout::PaintWindowFrame(gfx::Canvas* canvas,
-                                           gfx::Rect local_bounds,
-                                           gfx::Rect titlebar_bounds,
-                                           bool active) {
-  GetFrameProvider()->PaintWindowFrame(
-      canvas, local_bounds, titlebar_bounds.bottom(), active, GetInputInsets());
-}
-
-gfx::Rect LinuxCSDFrameLayout::GetWindowContentBounds() const {
-  gfx::Rect content_bounds = window_->widget()->GetWindowBoundsInScreen();
-  content_bounds.Inset(RestoredFrameBorderInsets());
-  return content_bounds;
-}
-
-SkRRect LinuxCSDFrameLayout::GetRoundedWindowContentBounds() const {
-  SkRect rect = gfx::RectToSkRect(GetWindowContentBounds());
+SkRRect LinuxFrameLayout::GetRoundedWindowBounds() const {
+  SkRect rect = gfx::RectToSkRect(GetWindowBounds());
   SkRRect rrect;
-
-  if (!window_->IsMaximized()) {
-    float radius = GetFrameProvider()->GetTopCornerRadiusDip();
+  float radius = GetTopCornerRadiusDip();
+  if (radius > 0) {
     SkPoint round_point{radius, radius};
     SkPoint radii[] = {round_point, round_point, {}, {}};
     rrect.setRectRadii(rect, radii);
   } else {
     rrect.setRect(rect);
   }
-
   return rrect;
 }
 
-int LinuxCSDFrameLayout::GetTranslucentTopAreaHeight() const {
+// Base implementation is suitable for X11/views without shadows
+LinuxFrameLayout::LinuxFrameLayout(NativeWindowViews* window)
+    : window_(window) {
+  host_supports_client_frame_shadow_ = false;
+}
+
+LinuxFrameLayout::~LinuxFrameLayout() = default;
+
+gfx::Insets LinuxFrameLayout::RestoredFrameBorderInsets() const {
+  return gfx::Insets();
+}
+
+gfx::Insets LinuxFrameLayout::GetInputInsets() const {
+  return gfx::Insets(kResizeInsideBoundsSize);
+}
+
+bool LinuxFrameLayout::IsShowingShadow() const {
+  return host_supports_client_frame_shadow_ && !window_->IsMaximized() &&
+         !window_->IsFullscreen();
+}
+
+bool LinuxFrameLayout::SupportsClientFrameShadow() const {
+  return host_supports_client_frame_shadow_;
+}
+
+bool LinuxFrameLayout::tiled() const {
+  return tiled_;
+}
+
+void LinuxFrameLayout::set_tiled(bool tiled) {
+  tiled_ = tiled;
+}
+
+gfx::Rect LinuxFrameLayout::GetWindowBounds() const {
+  gfx::Rect bounds = window_->widget()->GetWindowBoundsInScreen();
+  bounds.Inset(RestoredFrameBorderInsets());
+  return bounds;
+}
+
+float LinuxFrameLayout::GetTopCornerRadiusDip() const {
   return 0;
 }
 
-ui::WindowFrameProvider* LinuxCSDFrameLayout::GetFrameProvider() const {
+int LinuxFrameLayout::GetTranslucentTopAreaHeight() const {
+  return 0;
+}
+
+gfx::Insets LinuxFrameLayout::NormalizeBorderInsets(
+    const gfx::Insets& frame_insets,
+    const gfx::Insets& input_insets) const {
+  auto expand_if_visible = [](int side_thickness, int min_band) {
+    return side_thickness > 0 ? std::max(side_thickness, min_band) : 0;
+  };
+
+  // Ensure hit testing for resize targets works
+  // even if borders/shadows are absent on some edges.
+  gfx::Insets merged;
+  merged.set_top(expand_if_visible(frame_insets.top(), input_insets.top()));
+  merged.set_left(expand_if_visible(frame_insets.left(), input_insets.left()));
+  merged.set_bottom(
+      expand_if_visible(frame_insets.bottom(), input_insets.bottom()));
+  merged.set_right(
+      expand_if_visible(frame_insets.right(), input_insets.right()));
+
+  return base::i18n::IsRTL() ? gfx::Insets::TLBR(merged.top(), merged.right(),
+                                                 merged.bottom(), merged.left())
+                             : merged;
+}
+
+// Used for a native-like frame with a FrameProvider
+LinuxCSDNativeFrameLayout::LinuxCSDNativeFrameLayout(NativeWindowViews* window)
+    : LinuxFrameLayout(window) {
+  host_supports_client_frame_shadow_ = CheckClientFrameShadowSupport(window);
+}
+
+LinuxCSDNativeFrameLayout::~LinuxCSDNativeFrameLayout() = default;
+
+gfx::Insets LinuxCSDNativeFrameLayout::RestoredFrameBorderInsets() const {
+  const gfx::Insets input_insets = GetInputInsets();
+  const gfx::Insets frame_insets = GetFrameProvider()->GetFrameThicknessDip();
+  return NormalizeBorderInsets(frame_insets, input_insets);
+}
+
+gfx::Insets LinuxCSDNativeFrameLayout::GetInputInsets() const {
+  return gfx::Insets(IsShowingShadow() ? kResizeBorder : 0);
+}
+
+float LinuxCSDNativeFrameLayout::GetTopCornerRadiusDip() const {
+  return window_->IsMaximized() ? 0
+                                : GetFrameProvider()->GetTopCornerRadiusDip();
+}
+
+ui::WindowFrameProvider* LinuxCSDNativeFrameLayout::GetFrameProvider() const {
   return ui::LinuxUiTheme::GetForProfile(nullptr)->GetWindowFrameProvider(
       !host_supports_client_frame_shadow_, tiled(), window_->IsMaximized());
 }
 
-LinuxUndecoratedFrameLayout::LinuxUndecoratedFrameLayout(
-    NativeWindowViews* window)
-    : window_(window) {}
-
-gfx::Insets LinuxUndecoratedFrameLayout::RestoredFrameBorderInsets() const {
-  return gfx::Insets();
+// Used for Chromium-like custom CSD
+LinuxCSDCustomFrameLayout::LinuxCSDCustomFrameLayout(NativeWindowViews* window)
+    : LinuxFrameLayout(window) {
+  host_supports_client_frame_shadow_ = CheckClientFrameShadowSupport(window);
 }
 
-gfx::Insets LinuxUndecoratedFrameLayout::GetInputInsets() const {
-  return gfx::Insets(kResizeInsideBoundsSize);
+LinuxCSDCustomFrameLayout::~LinuxCSDCustomFrameLayout() = default;
+
+gfx::Insets LinuxCSDCustomFrameLayout::RestoredFrameBorderInsets() const {
+  const gfx::Insets input_insets = GetInputInsets();
+  const bool showing_shadow = IsShowingShadow();
+  const auto shadow_values = (showing_shadow && !tiled())
+                                 ? GetFrameShadowValuesLinux(/*active=*/true)
+                                 : gfx::ShadowValues();
+  const gfx::Insets frame_insets = GetRestoredFrameBorderInsetsLinux(
+      showing_shadow, kDefaultCustomFrameBorder, shadow_values, input_insets);
+  return NormalizeBorderInsets(frame_insets, input_insets);
 }
 
-bool LinuxUndecoratedFrameLayout::SupportsClientFrameShadow() const {
-  return false;
+gfx::Insets LinuxCSDCustomFrameLayout::GetInputInsets() const {
+  return gfx::Insets(IsShowingShadow() ? kResizeBorder : 0);
 }
 
-bool LinuxUndecoratedFrameLayout::tiled() const {
-  return tiled_;
-}
-
-void LinuxUndecoratedFrameLayout::set_tiled(bool tiled) {
-  tiled_ = tiled;
-}
-
-void LinuxUndecoratedFrameLayout::PaintWindowFrame(gfx::Canvas* canvas,
-                                                   gfx::Rect local_bounds,
-                                                   gfx::Rect titlebar_bounds,
-                                                   bool active) {
-  // No-op
-}
-
-gfx::Rect LinuxUndecoratedFrameLayout::GetWindowContentBounds() const {
-  // With no transparent insets, widget bounds and logical bounds match.
-  return window_->widget()->GetWindowBoundsInScreen();
-}
-
-SkRRect LinuxUndecoratedFrameLayout::GetRoundedWindowContentBounds() const {
-  SkRRect rrect;
-  rrect.setRect(gfx::RectToSkRect(GetWindowContentBounds()));
-  return rrect;
-}
-
-int LinuxUndecoratedFrameLayout::GetTranslucentTopAreaHeight() const {
-  return 0;
-}
-
-ui::WindowFrameProvider* LinuxUndecoratedFrameLayout::GetFrameProvider() const {
-  return nullptr;
+gfx::ShadowValues GetFrameShadowValuesLinux(bool active) {
+  const int elevation = views::LayoutProvider::Get()->GetShadowElevationMetric(
+      active ? views::Emphasis::kMaximum : views::Emphasis::kMedium);
+  return gfx::ShadowValue::MakeMdShadowValues(elevation);
 }
 
 }  // namespace electron

shell/browser/ui/views/linux_frame_layout.h

@@ -8,110 +8,96 @@
 
 #include <memory>
 
-#include "base/i18n/rtl.h"
-#include "shell/browser/linux/x11_util.h"
-#include "shell/browser/native_window_views.h"
-#include "shell/browser/ui/electron_desktop_window_tree_host_linux.h"
+#include "base/memory/raw_ptr.h"
 #include "third_party/skia/include/core/SkRRect.h"
-#include "ui/base/ozone_buildflags.h"
-#include "ui/gfx/canvas.h"
-#include "ui/gfx/geometry/insets.h"
-#include "ui/linux/linux_ui.h"
+#include "ui/gfx/shadow_value.h"
 #include "ui/linux/window_frame_provider.h"
 
+namespace gfx {
+class Insets;
+class Rect;
+}  // namespace gfx
+
 namespace electron {
 
 class NativeWindowViews;
 
-// Shared helper for CSD layout and frame painting on Linux (shadows, resize
-// regions, titlebars, etc.). Also helps views determine insets and perform
-// bounds conversions between widget and logical coordinates.
+// Shared helper for CSD layout on Linux (shadows, resize regions, titlebars,
+// etc.). Also helps views determine insets and perform bounds conversions
+// between widget and logical coordinates.
+//
+// The base class is concrete and suitable as-is for the undecorated case (X11,
+// translucent windows, or windows without shadows). CSD subclasses override
+// the methods that differ.
 class LinuxFrameLayout {
  public:
-  virtual ~LinuxFrameLayout() = default;
+  enum class CSDStyle {
+    kNativeFrame,
+    kCustom,
+  };
+
+  explicit LinuxFrameLayout(NativeWindowViews* window);
+  virtual ~LinuxFrameLayout();
 
   static std::unique_ptr<LinuxFrameLayout> Create(NativeWindowViews* window,
-                                                  bool wants_shadow);
+                                                  bool wants_shadow,
+                                                  CSDStyle csd_style);
 
-  // Insets from the transparent widget border to the opaque part of the window
-  virtual gfx::Insets RestoredFrameBorderInsets() const = 0;
-  // Insets for parts of the surface that should be counted for user input
-  virtual gfx::Insets GetInputInsets() const = 0;
+  // Insets from the transparent widget border to the opaque part of the window.
+  virtual gfx::Insets RestoredFrameBorderInsets() const;
+  // Insets for parts of the surface that should be counted for user input.
+  virtual gfx::Insets GetInputInsets() const;
+  // Insets to use for non-client resize hit-testing.
+  gfx::Insets GetResizeBorderInsets() const;
 
-  virtual bool SupportsClientFrameShadow() const = 0;
+  bool IsShowingShadow() const;
+  bool SupportsClientFrameShadow() const;
 
-  virtual bool tiled() const = 0;
-  virtual void set_tiled(bool tiled) = 0;
+  bool tiled() const;
+  void set_tiled(bool tiled);
 
-  virtual void PaintWindowFrame(gfx::Canvas* canvas,
-                                gfx::Rect local_bounds,
-                                gfx::Rect titlebar_bounds,
-                                bool active) = 0;
+  // The logical bounds of the window interior.
+  gfx::Rect GetWindowBounds() const;
+  // The logical window bounds as a rounded rect with corner radii applied.
+  SkRRect GetRoundedWindowBounds() const;
+  // The corner radius of the top corners of the window, in DIPs.
+  virtual float GetTopCornerRadiusDip() const;
 
-  // The logical bounds of the window
-  virtual gfx::Rect GetWindowContentBounds() const = 0;
-  // The logical bounds as a rounded rect with corner radii applied
-  virtual SkRRect GetRoundedWindowContentBounds() const = 0;
+  int GetTranslucentTopAreaHeight() const;
 
-  virtual int GetTranslucentTopAreaHeight() const = 0;
+ protected:
+  gfx::Insets NormalizeBorderInsets(const gfx::Insets& frame_insets,
+                                    const gfx::Insets& input_insets) const;
 
-  virtual ui::WindowFrameProvider* GetFrameProvider() const = 0;
-};
-
-// Client-side decoration (CSD) Linux frame layout implementation.
-class LinuxCSDFrameLayout : public LinuxFrameLayout {
- public:
-  explicit LinuxCSDFrameLayout(NativeWindowViews* window);
-  ~LinuxCSDFrameLayout() override = default;
-
-  gfx::Insets RestoredFrameBorderInsets() const override;
-  gfx::Insets GetInputInsets() const override;
-  bool SupportsClientFrameShadow() const override;
-  bool tiled() const override;
-  void set_tiled(bool tiled) override;
-  void PaintWindowFrame(gfx::Canvas* canvas,
-                        gfx::Rect local_bounds,
-                        gfx::Rect titlebar_bounds,
-                        bool active) override;
-  gfx::Rect GetWindowContentBounds() const override;
-  SkRRect GetRoundedWindowContentBounds() const override;
-  int GetTranslucentTopAreaHeight() const override;
-  ui::WindowFrameProvider* GetFrameProvider() const override;
-
- private:
   raw_ptr<NativeWindowViews> window_;
   bool tiled_ = false;
   bool host_supports_client_frame_shadow_ = false;
 };
 
-// No-decoration Linux frame layout implementation.
-//
-// Intended for cases where we do not allocate a transparent inset area around
-// the window (e.g. X11 / server-side decorations, or when insets are disabled).
-// All inset math returns 0 and frame painting is skipped.
-class LinuxUndecoratedFrameLayout : public LinuxFrameLayout {
+// CSD strategy that uses the GTK window frame provider for metrics.
+class LinuxCSDNativeFrameLayout : public LinuxFrameLayout {
  public:
-  explicit LinuxUndecoratedFrameLayout(NativeWindowViews* window);
-  ~LinuxUndecoratedFrameLayout() override = default;
+  explicit LinuxCSDNativeFrameLayout(NativeWindowViews* window);
+  ~LinuxCSDNativeFrameLayout() override;
 
   gfx::Insets RestoredFrameBorderInsets() const override;
   gfx::Insets GetInputInsets() const override;
-  bool SupportsClientFrameShadow() const override;
-  bool tiled() const override;
-  void set_tiled(bool tiled) override;
-  void PaintWindowFrame(gfx::Canvas* canvas,
-                        gfx::Rect local_bounds,
-                        gfx::Rect titlebar_bounds,
-                        bool active) override;
-  gfx::Rect GetWindowContentBounds() const override;
-  SkRRect GetRoundedWindowContentBounds() const override;
-  int GetTranslucentTopAreaHeight() const override;
-  ui::WindowFrameProvider* GetFrameProvider() const override;
-
- private:
-  raw_ptr<NativeWindowViews> window_;
-  bool tiled_ = false;
+  float GetTopCornerRadiusDip() const override;
+  ui::WindowFrameProvider* GetFrameProvider() const;
 };
+
+// CSD strategy that uses custom metrics, similar to those used in Chromium.
+class LinuxCSDCustomFrameLayout : public LinuxFrameLayout {
+ public:
+  explicit LinuxCSDCustomFrameLayout(NativeWindowViews* window);
+  ~LinuxCSDCustomFrameLayout() override;
+
+  gfx::Insets RestoredFrameBorderInsets() const override;
+  gfx::Insets GetInputInsets() const override;
+};
+
+gfx::ShadowValues GetFrameShadowValuesLinux(bool active);
+
 }  // namespace electron
 
 #endif  // ELECTRON_SHELL_BROWSER_UI_VIEWS_LINUX_FRAME_LAYOUT_H_

shell/browser/ui/views/opaque_frame_view.cc

@@ -5,22 +5,24 @@
 #include "shell/browser/ui/views/opaque_frame_view.h"
 
 #include "base/containers/adapters.h"
-#include "base/i18n/rtl.h"
+#include "chrome/browser/ui/views/frame/browser_frame_view_paint_utils_linux.h"  // nogncheck
 #include "chrome/browser/ui/views/frame/opaque_browser_frame_view_layout.h"  // nogncheck
 #include "chrome/grit/generated_resources.h"
 #include "components/strings/grit/components_strings.h"
 #include "shell/browser/native_window_views.h"
 #include "shell/browser/ui/views/caption_button_placeholder_container.h"
+#include "third_party/skia/include/core/SkRRect.h"
 #include "ui/base/hit_test.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/metadata/metadata_impl_macros.h"
 #include "ui/compositor/layer.h"
 #include "ui/gfx/font_list.h"
-#include "ui/linux/linux_ui.h"
+#include "ui/gfx/geometry/insets_f.h"
+#include "ui/gfx/geometry/skia_conversions.h"
 #include "ui/views/accessibility/view_accessibility.h"
 #include "ui/views/background.h"
 #include "ui/views/widget/widget.h"
-#include "ui/views/widget/widget_delegate.h"
+#include "ui/views/window/frame_background.h"
 #include "ui/views/window/frame_caption_button.h"
 #include "ui/views/window/vector_icons/vector_icons.h"
 
@@ -55,12 +57,14 @@ const int kCaptionButtonBottomPadding = 3;
 // The content edge images have a shadow built into them.
 const int OpaqueFrameView::kContentEdgeShadowThickness = 2;
 
-OpaqueFrameView::OpaqueFrameView() = default;
+OpaqueFrameView::OpaqueFrameView()
+    : frame_background_(std::make_unique<views::FrameBackground>()) {}
 OpaqueFrameView::~OpaqueFrameView() = default;
 
 void OpaqueFrameView::Init(NativeWindowViews* window, views::Widget* frame) {
   FramelessView::Init(window, frame);
-  linux_frame_layout_ = LinuxFrameLayout::Create(window, window->HasShadow());
+  linux_frame_layout_ = LinuxFrameLayout::Create(
+      window, window->HasShadow(), LinuxFrameLayout::CSDStyle::kCustom);
 
   // Unretained() is safe because the subscription is saved into an instance
   // member and thus will be cancelled upon the instance's destruction.
@@ -98,9 +102,8 @@ void OpaqueFrameView::Init(NativeWindowViews* window, views::Widget* frame) {
 }
 
 int OpaqueFrameView::ResizingBorderHitTest(const gfx::Point& point) {
-  auto insets = RestoredFrameBorderInsets();
   return ResizingBorderHitTestImpl(
-      point, insets.IsEmpty() ? linux_frame_layout_->GetInputInsets() : insets);
+      point, linux_frame_layout_->GetResizeBorderInsets());
 }
 
 void OpaqueFrameView::InvalidateCaptionButtons() {
@@ -200,14 +203,31 @@ void OpaqueFrameView::OnPaint(gfx::Canvas* canvas) {
   if (frame()->IsFullscreen())
     return;
 
-  // Titlebar height must be at least the frame border insets to avoid
-  // a negative height calculation in the GTK frame provider. We add 1 to
-  // ensure it's always positive even when insets are 0.
-  int top_area_height = RestoredFrameBorderInsets().top() + 1;
+  const bool active = ShouldPaintAsActive();
+  const gfx::Insets border = RestoredFrameBorderInsets();
+  const bool showing_shadow = linux_frame_layout_->IsShowingShadow();
+  gfx::RectF bounds_dip(GetLocalBounds());
+  if (showing_shadow) {
+    bounds_dip.Inset(gfx::InsetsF(border));
+  }
 
-  linux_frame_layout_->PaintWindowFrame(
-      canvas, GetLocalBounds(), gfx::Rect(0, 0, width(), top_area_height),
-      ShouldPaintAsActive());
+  // TODO: support roundedCorners.
+  float radius_dip = 0;
+  SkVector radii[4]{{radius_dip, radius_dip}, {radius_dip, radius_dip}, {}, {}};
+  SkRRect clip;
+  clip.setRectRadii(gfx::RectFToSkRect(bounds_dip), radii);
+
+  frame_background_->set_frame_color(GetFrameColor());
+  frame_background_->set_use_custom_frame(true);
+  frame_background_->set_is_active(active);
+  frame_background_->set_top_area_height(GetTopAreaHeight());
+
+  const bool draw_shadow = showing_shadow && !linux_frame_layout_->tiled();
+  auto shadow_values =
+      draw_shadow ? GetFrameShadowValuesLinux(active) : gfx::ShadowValues();
+  ::PaintRestoredFrameBorderLinux(*canvas, *this, frame_background_.get(), clip,
+                                  showing_shadow, active, border, shadow_values,
+                                  linux_frame_layout_->tiled());
 
   if (!window()->IsWindowControlsOverlayEnabled())
     return;

shell/browser/ui/views/opaque_frame_view.h

@@ -20,6 +20,10 @@
 
 class CaptionButtonPlaceholderContainer;
 
+namespace views {
+class FrameBackground;
+}
+
 namespace electron {
 
 class NativeWindowViews;
@@ -166,6 +170,7 @@ class OpaqueFrameView : public FramelessView {
                               bool is_leading_button) const;
 
   std::unique_ptr<LinuxFrameLayout> linux_frame_layout_;
+  std::unique_ptr<views::FrameBackground> frame_background_;
 
   // Window controls.
   raw_ptr<views::Button> minimize_button_;

spec/api-autoupdater-darwin-spec.ts

@@ -403,7 +403,7 @@ ifdescribe(shouldRunCodesignTests)('autoUpdater behavior', function () {
       });
     });
 
-    it('should clean up old staged update directories when a new update is downloaded', async () => {
+    it('should preserve the staged update directory and prune orphaned ones when a new update is downloaded', async () => {
       // Clean up any existing update directories before the test
       await cleanSquirrelCache();
 
@@ -419,16 +419,23 @@ ifdescribe(shouldRunCodesignTests)('autoUpdater behavior', function () {
         }, async (_, updateZipPath3) => {
           let updateCount = 0;
           let downloadCount = 0;
-          let directoriesDuringSecondDownload: string[] = [];
+          let dirsDuringFirstDownload: string[] = [];
+          let dirsDuringSecondDownload: string[] = [];
 
           server.get('/update-file', async (req, res) => {
             downloadCount++;
-            // When the second download request arrives, Squirrel has already
-            // called uniqueTemporaryDirectoryForUpdate which (with our patch)
-            // cleans up old directories before creating the new one.
-            // Without the patch, both directories would exist at this point.
-            if (downloadCount === 2) {
-              directoriesDuringSecondDownload = await getUpdateDirectoriesInCache();
+            // Snapshot update directories at the moment each download begins.
+            // By this point uniqueTemporaryDirectoryForUpdate has already run
+            // (prune + mkdtemp). We want to verify:
+            //   1st download: 1 dir (nothing to preserve, nothing to prune)
+            //   2nd download: 2 dirs (staged dir from 1st check is preserved
+            //                 so quitAndInstall stays safe, + new temp dir)
+            // The count never exceeds 2 across repeated checks — orphaned dirs
+            // (no longer referenced by ShipItState.plist) get pruned.
+            if (downloadCount === 1) {
+              dirsDuringFirstDownload = await getUpdateDirectoriesInCache();
+            } else if (downloadCount === 2) {
+              dirsDuringSecondDownload = await getUpdateDirectoriesInCache();
             }
             res.download(updateCount > 1 ? updateZipPath3 : updateZipPath2);
           });
@@ -455,15 +462,181 @@ ifdescribe(shouldRunCodesignTests)('autoUpdater behavior', function () {
 
           await relaunchPromise;
 
-          // During the second download, the old staged update directory should
-          // have been cleaned up. With our patch, there should be exactly 1
-          // directory (the new one). Without the patch, there would be 2.
-          expect(directoriesDuringSecondDownload).to.have.lengthOf(1,
-            `Expected 1 update directory during second download but found ${directoriesDuringSecondDownload.length}: ${directoriesDuringSecondDownload.join(', ')}`);
+          // First download: exactly one temp dir (the first update).
+          expect(dirsDuringFirstDownload).to.have.lengthOf(1,
+            `Expected 1 update directory during first download but found ${dirsDuringFirstDownload.length}: ${dirsDuringFirstDownload.join(', ')}`);
+
+          // Second download: exactly two — the staged one preserved + the new
+          // one. Crucially the first download's directory must still be present,
+          // otherwise a mid-download quitAndInstall would find a dangling
+          // ShipItState.plist.
+          expect(dirsDuringSecondDownload).to.have.lengthOf(2,
+            `Expected 2 update directories during second download (staged + new) but found ${dirsDuringSecondDownload.length}: ${dirsDuringSecondDownload.join(', ')}`);
+          expect(dirsDuringSecondDownload).to.include(dirsDuringFirstDownload[0],
+            'The staged update directory from the first download must be preserved during the second download');
         });
       });
     });
 
+    it('should keep the update directory count bounded across repeated checks', async () => {
+      // Verifies the orphan prune actually fires: after a second download
+      // completes and rewrites ShipItState.plist, the first directory is no
+      // longer referenced and must be removed when a third check begins.
+      // Without this, directories would accumulate forever.
+      await cleanSquirrelCache();
+
+      await withUpdatableApp({
+        nextVersion: '2.0.0',
+        startFixture: 'update-triple-stack',
+        endFixture: 'update-triple-stack'
+      }, async (appPath, updateZipPath2) => {
+        await withUpdatableApp({
+          nextVersion: '3.0.0',
+          startFixture: 'update-triple-stack',
+          endFixture: 'update-triple-stack'
+        }, async (_, updateZipPath3) => {
+          await withUpdatableApp({
+            nextVersion: '4.0.0',
+            startFixture: 'update-triple-stack',
+            endFixture: 'update-triple-stack'
+          }, async (__, updateZipPath4) => {
+            let downloadCount = 0;
+            const dirsPerDownload: string[][] = [];
+
+            server.get('/update-file', async (req, res) => {
+              downloadCount++;
+              // Snapshot after prune+mkdtemp but before the payload transfers.
+              dirsPerDownload.push(await getUpdateDirectoriesInCache());
+              const zips = [updateZipPath2, updateZipPath3, updateZipPath4];
+              res.download(zips[Math.min(downloadCount, zips.length) - 1]);
+            });
+            server.get('/update-check', (req, res) => {
+              res.json({
+                url: `http://localhost:${port}/update-file`,
+                name: 'My Release Name',
+                notes: 'Theses are some release notes innit',
+                pub_date: (new Date()).toString()
+              });
+            });
+            const relaunchPromise = new Promise<void>((resolve) => {
+              server.get('/update-check/updated/:version', (req, res) => {
+                res.status(204).send();
+                resolve();
+              });
+            });
+
+            const launchResult = await launchApp(appPath, [`http://localhost:${port}/update-check`]);
+            logOnError(launchResult, () => {
+              expect(launchResult).to.have.property('code', 0);
+              expect(launchResult.out).to.include('Update Downloaded');
+            });
+
+            await relaunchPromise;
+            expect(requests[requests.length - 1].url).to.equal('/update-check/updated/4.0.0');
+
+            expect(dirsPerDownload).to.have.lengthOf(3);
+
+            // 1st: fresh cache, 1 dir.
+            expect(dirsPerDownload[0]).to.have.lengthOf(1,
+              `1st download: ${dirsPerDownload[0].join(', ')}`);
+
+            // 2nd: staged (1st) preserved + new = 2 dirs.
+            expect(dirsPerDownload[1]).to.have.lengthOf(2,
+              `2nd download: ${dirsPerDownload[1].join(', ')}`);
+            expect(dirsPerDownload[1]).to.include(dirsPerDownload[0][0]);
+
+            // 3rd: 1st is now orphaned (plist points to 2nd) — must be pruned.
+            // Staged (2nd) preserved + new = still 2 dirs. Bounded.
+            expect(dirsPerDownload[2]).to.have.lengthOf(2,
+              `3rd download: ${dirsPerDownload[2].join(', ')}`);
+            expect(dirsPerDownload[2]).to.not.include(dirsPerDownload[0][0],
+              'The first (now orphaned) update directory must be pruned on the third check');
+            const secondDir = dirsPerDownload[1].find(d => d !== dirsPerDownload[0][0]);
+            expect(dirsPerDownload[2]).to.include(secondDir,
+              'The second (currently staged) update directory must be preserved on the third check');
+          });
+        });
+      });
+    });
+
+    // Regression test for https://github.com/electron/electron/issues/50200
+    //
+    // When checkForUpdates() is called again after an update has been staged,
+    // Squirrel creates a new temporary directory and prunes old ones. If the
+    // prune removes the directory that ShipItState.plist references while the
+    // second download is still in flight, a subsequent quitAndInstall() will
+    // fail with ENOENT and the app will never relaunch.
+    it('should install the staged update when quitAndInstall is called while a second check is in flight', async () => {
+      await cleanSquirrelCache();
+
+      await withUpdatableApp({
+        nextVersion: '2.0.0',
+        startFixture: 'update-race',
+        endFixture: 'update-race'
+      }, async (appPath, updateZipPath) => {
+        let downloadCount = 0;
+        let stalledResponse: express.Response | null = null;
+
+        server.get('/update-file', (req, res) => {
+          downloadCount++;
+          if (downloadCount === 1) {
+            // First download completes normally and stages the update.
+            res.download(updateZipPath);
+          } else {
+            // Second download: stall indefinitely to simulate a slow
+            // network. This keeps the second check "in progress" when
+            // quitAndInstall() fires. Hold onto the response so we can
+            // clean it up later.
+            stalledResponse = res;
+          }
+        });
+        server.get('/update-check', (req, res) => {
+          res.json({
+            url: `http://localhost:${port}/update-file`,
+            name: 'My Release Name',
+            notes: 'Theses are some release notes innit',
+            pub_date: (new Date()).toString()
+          });
+        });
+        const relaunchPromise = new Promise<void>((resolve) => {
+          server.get('/update-check/updated/:version', (req, res) => {
+            res.status(204).send();
+            resolve();
+          });
+        });
+
+        const launchResult = await launchApp(appPath, [`http://localhost:${port}/update-check`]);
+        logOnError(launchResult, () => {
+          expect(launchResult).to.have.property('code', 0);
+          expect(launchResult.out).to.include('Update Downloaded');
+          expect(launchResult.out).to.include('Calling quitAndInstall mid-download');
+          // First check + first download + second check + stalled second download.
+          expect(requests).to.have.lengthOf(4);
+          expect(requests[0]).to.have.property('url', '/update-check');
+          expect(requests[1]).to.have.property('url', '/update-file');
+          expect(requests[2]).to.have.property('url', '/update-check');
+          expect(requests[3]).to.have.property('url', '/update-file');
+          // The second download must have been in flight (never completed)
+          // when quitAndInstall was called.
+          expect(launchResult.out).to.not.include('Unexpected second download completion');
+        });
+
+        // Unblock the stalled response now that the initial app has exited
+        // so the express server can shut down cleanly.
+        if (stalledResponse) {
+          (stalledResponse as express.Response).status(500).end();
+        }
+
+        // The originally staged update (2.0.0) must have been applied and
+        // the app must relaunch, proving the staged update directory was
+        // not pruned out from under ShipItState.plist.
+        await relaunchPromise;
+        expect(requests).to.have.lengthOf(5);
+        expect(requests[4].url).to.equal('/update-check/updated/2.0.0');
+        expect(requests[4].header('user-agent')).to.include('Electron/');
+      });
+    });
+
     it('should update to lower version numbers', async () => {
       await withUpdatableApp({
         nextVersion: '0.0.1',

spec/chromium-spec.ts

@@ -567,14 +567,7 @@ describe('command line switches', () => {
     });
 
     it('creates startup trace', async () => {
-      // node.async_hooks relies on %trace builtin to log trace points from JS
-      // https://github.com/nodejs/node/blob/8b199eef3dd4de910a6521adc42ae611a62a19e1/lib/internal/trace_events_async_hooks.js#L48-L53
-      // The phase event arg TRACE_EVENT_PHASE_NESTABLE_ASYNC_(BEGIN | END) is not supported in v8_use_perfetto mode
-      // https://source.chromium.org/chromium/chromium/src/+/main:v8/src/builtins/builtins-trace.cc;l=201-216
-      // and leads to the following error: TypeError: Trace event phase must be a number.
-      // TODO: Identify why the error started appearing with roll https://github.com/electron/electron/pull/47561
-      // given both v8_use_perfetto has been enabled before the roll and builtins-trace macro hasn't changed.
-      const rc = await startRemoteControlApp(['--trace-startup="*,-node.async_hooks"', `--trace-startup-file=${outputFilePath}`, '--trace-startup-duration=1', '--enable-logging']);
+      const rc = await startRemoteControlApp(['--trace-startup=*', `--trace-startup-file=${outputFilePath}`, '--trace-startup-duration=1', '--enable-logging']);
       const stderrComplete = new Promise<string>(resolve => {
         let stderr = '';
         rc.process.stderr!.on('data', (chunk) => {

spec/fixtures/auto-update/update-race/index.js

@@ -0,0 +1,82 @@
+const { app, autoUpdater } = require('electron');
+
+const fs = require('node:fs');
+const path = require('node:path');
+
+process.on('uncaughtException', (err) => {
+  console.error(err);
+  process.exit(1);
+});
+
+let installInvoked = false;
+
+autoUpdater.on('error', (err) => {
+  // Once quitAndInstall() has been invoked the second in-flight check may
+  // surface a cancellation/network error as the process tears down; ignore
+  // errors after that point so we test the actual install race, not teardown.
+  if (installInvoked) {
+    console.log('Ignoring post-install error:', err && err.message);
+    return;
+  }
+  console.error(err);
+  process.exit(1);
+});
+
+const urlPath = path.resolve(__dirname, '../../../../url.txt');
+let feedUrl = process.argv[1];
+
+if (feedUrl === 'remain-open') {
+  // Hold the event loop
+  setInterval(() => {});
+} else {
+  if (!feedUrl || !feedUrl.startsWith('http')) {
+    feedUrl = `${fs.readFileSync(urlPath, 'utf8')}/${app.getVersion()}`;
+  } else {
+    fs.writeFileSync(urlPath, `${feedUrl}/updated`);
+  }
+
+  autoUpdater.setFeedURL({
+    url: feedUrl
+  });
+
+  autoUpdater.checkForUpdates();
+
+  autoUpdater.on('update-available', () => {
+    console.log('Update Available');
+  });
+
+  let downloadedOnce = false;
+
+  autoUpdater.on('update-downloaded', () => {
+    console.log('Update Downloaded');
+    if (!downloadedOnce) {
+      downloadedOnce = true;
+      // Simulate a periodic update check firing after an update was already
+      // staged. The test server is expected to stall this second download so
+      // that it remains in flight while we call quitAndInstall().
+      // The short delay lets checkForUpdatesCommand's RACCommand executing
+      // state settle; calling immediately would hit the command's "disabled"
+      // guard since RACCommand disallows concurrent execution.
+      setTimeout(() => {
+        autoUpdater.checkForUpdates();
+        // Give Squirrel enough time to enter the second check (creating a new
+        // temporary directory, which with the regression prunes the directory
+        // that the staged update lives in) before invoking the install.
+        setTimeout(() => {
+          console.log('Calling quitAndInstall mid-download');
+          installInvoked = true;
+          autoUpdater.quitAndInstall();
+        }, 3000);
+      }, 1000);
+    } else {
+      // Should not reach here — the second download is stalled on purpose.
+      console.log('Unexpected second download completion');
+      autoUpdater.quitAndInstall();
+    }
+  });
+
+  autoUpdater.on('update-not-available', () => {
+    console.error('No update available');
+    process.exit(1);
+  });
+}

spec/fixtures/auto-update/update-race/package.json

@@ -0,0 +1,5 @@
+{
+  "name": "electron-test-update-race",
+  "version": "1.0.0",
+  "main": "./index.js"
+}

spec/fixtures/auto-update/update-triple-stack/index.js

@@ -0,0 +1,57 @@
+const { app, autoUpdater } = require('electron');
+
+const fs = require('node:fs');
+const path = require('node:path');
+
+process.on('uncaughtException', (err) => {
+  console.error(err);
+  process.exit(1);
+});
+
+autoUpdater.on('error', (err) => {
+  console.error(err);
+  process.exit(1);
+});
+
+const urlPath = path.resolve(__dirname, '../../../../url.txt');
+let feedUrl = process.argv[1];
+
+if (feedUrl === 'remain-open') {
+  // Hold the event loop
+  setInterval(() => {});
+} else {
+  if (!feedUrl || !feedUrl.startsWith('http')) {
+    feedUrl = `${fs.readFileSync(urlPath, 'utf8')}/${app.getVersion()}`;
+  } else {
+    fs.writeFileSync(urlPath, `${feedUrl}/updated`);
+  }
+
+  autoUpdater.setFeedURL({
+    url: feedUrl
+  });
+
+  autoUpdater.checkForUpdates();
+
+  autoUpdater.on('update-available', () => {
+    console.log('Update Available');
+  });
+
+  let updateStackCount = 0;
+
+  autoUpdater.on('update-downloaded', () => {
+    updateStackCount++;
+    console.log('Update Downloaded');
+    if (updateStackCount > 2) {
+      autoUpdater.quitAndInstall();
+    } else {
+      setTimeout(() => {
+        autoUpdater.checkForUpdates();
+      }, 1000);
+    }
+  });
+
+  autoUpdater.on('update-not-available', () => {
+    console.error('No update available');
+    process.exit(1);
+  });
+}

spec/fixtures/auto-update/update-triple-stack/package.json

@@ -0,0 +1,5 @@
+{
+  "name": "electron-test-update-triple-stack",
+  "version": "1.0.0",
+  "main": "./index.js"
+}