chore: bump chromium to 143.0.7485.0 (main) (#48618)

* chore: bump chromium in DEPS to 143.0.7485.0

* chore: update allow_disabling_blink_scheduler_throttling_per_renderview.patch

Move SetSupportsDraggableRegions mojom IPC from chrome/ and extensions/ to blink/ | https://chromium-review.googlesource.com/c/chromium/src/+/7043264

Patch applied manually due to context shear

* Move SetSupportsDraggableRegions mojom IPC from chrome/ and extensions/ to blink/ | https://chromium-review.googlesource.com/c/chromium/src/+/7043264

* chore: e patches all

* chore: check for file existence before setting utime

* chore: stop disabling kWinDelaySpellcheckServiceInit

[cleanup] Remove feature WinDelaySpellcheckServiceInit | https://chromium-review.googlesource.com/c/chromium/src/+/7012087

This flag has been removed upstream. We've used it since c2d7164 (#38248)
to fix a crash originally described in 97b353a (#34993):

> Delaying spell check initialization is causing specs for
> 'custom dictionary word list API' to fail in Electron.

Since we haven't touched this in a few years, and since there's a
clear success criteria (a passing/failing spec), and since the patch
to restore this flag would be pretty large (~750 lines), I'm going
to try just removing the flag from our source to see if the spec
passes or fails.

* Revert "chore: stop disabling kWinDelaySpellcheckServiceInit"

This reverts commit e688880396.

Unfortunately, the crash persists.

* Revert [cleanup] Remove feature WinDelaySpellcheckServiceInit | https://chromium-review.googlesource.com/c/chromium/src/+/7012087

We currently need this feature

* fixup! chore: check for file existence before setting utime

* fixup! Move SetSupportsDraggableRegions mojom IPC from chrome/ and extensions/ to blink/ | https://chromium-review.googlesource.com/c/chromium/src/+/7043264

Address Robo's code review @ 64c7fd21ed

* fixup! fixup! chore: check for file existence before setting utime

fix: oops typo

---------

Co-authored-by: electron-roller[bot] <84116207+electron-roller[bot]@users.noreply.github.com>
Co-authored-by: Charles Kerr <charles@charleskerr.com>

DEPS

@@ -2,7 +2,7 @@ gclient_gn_args_from = 'src'
 
 vars = {
   'chromium_version':
-    '143.0.7483.0',
+    '143.0.7485.0',
   'node_version':
     'v22.20.0',
   'nan_version':

patches/chromium/.patches

@@ -141,3 +141,5 @@ revert_partial_remove_unused_prehandlemouseevent.patch
 allow_electron_to_depend_on_components_os_crypt_sync.patch
 expose_referrerscriptinfo_hostdefinedoptionsindex.patch
 chore_disable_protocol_handler_dcheck.patch
+fix_check_for_file_existence_before_setting_mtime.patch
+revert_cleanup_remove_feature_windelayspellcheckserviceinit.patch

patches/chromium/add_didinstallconditionalfeatures.patch

@@ -40,10 +40,10 @@ index 792ecdf43c810d19641251d3f5eeddccc4c621e9..99d368046177dd92c8b36743f461d348
                                                 int world_id) {
    for (auto& observer : observers_)
 diff --git a/content/renderer/render_frame_impl.h b/content/renderer/render_frame_impl.h
-index b0528c4f02bdbf54dc490f9163fbf4f24e3471db..542eddb03c98eac5c03c9bc208af2c863d552b2d 100644
+index ce1d8807d624b35fa63ef83e3a95c7cba8f1f22f..61d4ef338cc4c0e99c144d6d95bbe0adba9d3556 100644
 --- a/content/renderer/render_frame_impl.h
 +++ b/content/renderer/render_frame_impl.h
-@@ -604,6 +604,8 @@ class CONTENT_EXPORT RenderFrameImpl
+@@ -603,6 +603,8 @@ class CONTENT_EXPORT RenderFrameImpl
    void DidObserveLayoutShift(double score, bool after_input_or_scroll) override;
    void DidCreateScriptContext(v8::Local<v8::Context> context,
                                int world_id) override;

patches/chromium/allow_disabling_blink_scheduler_throttling_per_renderview.patch

@@ -6,11 +6,11 @@ Subject: allow disabling blink scheduler throttling per RenderView
 This allows us to disable throttling for hidden windows.
 
 diff --git a/content/browser/renderer_host/navigation_controller_impl_unittest.cc b/content/browser/renderer_host/navigation_controller_impl_unittest.cc
-index 94a67b61edb0bc2f3faa5db44e99d1493f38d5a0..e4a953c199f8c1e5d68e552f73c593d308946957 100644
+index 74b39146bbb8151a66ecb4f138f769fffc2525b2..a54948fa36c85c5c5dd04b9836951b1ce1279038 100644
 --- a/content/browser/renderer_host/navigation_controller_impl_unittest.cc
 +++ b/content/browser/renderer_host/navigation_controller_impl_unittest.cc
-@@ -168,6 +168,12 @@ class MockPageBroadcast : public blink::mojom::PageBroadcast {
+@@ -173,6 +173,12 @@ class MockPageBroadcast : public blink::mojom::PageBroadcast {
-               (std::optional<blink::NoiseToken> canvas_noise_token),
+               (bool supports_draggable_regions),
                (override));
  
 +  MOCK_METHOD(
@@ -51,10 +51,10 @@ index 7944fe64e0da112fc670358b75506bb199bb5e4a..0e3c16c6af2a078943e9f39808134ab2
    void SendRendererPreferencesToRenderer(
        const blink::RendererPreferences& preferences);
 diff --git a/content/browser/renderer_host/render_widget_host_view_aura.cc b/content/browser/renderer_host/render_widget_host_view_aura.cc
-index 08fc2be8e60d16de952ca7f76701ca4eea722c4b..8ad61a86598ac2249496e44113f31ebb21dc616b 100644
+index d97cbb4fd8e12bcbff19bf8cc8378997110c60c0..1041d25d5ef78abdcf7b85fe8457ec2a20e2a759 100644
 --- a/content/browser/renderer_host/render_widget_host_view_aura.cc
 +++ b/content/browser/renderer_host/render_widget_host_view_aura.cc
-@@ -578,8 +578,8 @@ void RenderWidgetHostViewAura::ShowImpl(PageVisibilityState page_visibility) {
+@@ -632,8 +632,8 @@ void RenderWidgetHostViewAura::ShowImpl(PageVisibilityState page_visibility) {
    // OnShowWithPageVisibility will not call NotifyHostAndDelegateOnWasShown,
    // which updates `visibility_`, unless the host is hidden. Make sure no update
    // is needed.
@@ -80,31 +80,31 @@ index 782bed0fdc08d57eceb059f398f253fab9233b1b..f1ab5b981ea68af1b11313e67f2c5060
    // This interface should only be implemented inside content.
    friend class RenderViewHostImpl;
 diff --git a/content/test/test_page_broadcast.h b/content/test/test_page_broadcast.h
-index 82ae7ab6279427e492ead6d1d386608eb9d3d844..2b79149bfcc0de968ffb45e310d697c5393f0d43 100644
+index 8762811ec25069ddd0c57e3ffb50d158532a39b1..f5cdae891cc3b98371ae18dbc119b5e7f379f2bf 100644
 --- a/content/test/test_page_broadcast.h
 +++ b/content/test/test_page_broadcast.h
-@@ -53,6 +53,7 @@ class TestPageBroadcast : public blink::mojom::PageBroadcast {
+@@ -54,6 +54,7 @@ class TestPageBroadcast : public blink::mojom::PageBroadcast {
-       const blink::ColorProviderColorMaps& color_provider_colors) override;
    void UpdateCanvasNoiseToken(
        std::optional<blink::NoiseToken> canvas_noise_token) override;
+   void SetSupportsDraggableRegions(bool supports_draggable_regions) override;
 +  void SetSchedulerThrottling(bool allowed) override {}
  
    mojo::AssociatedReceiver<blink::mojom::PageBroadcast> receiver_;
  };
 diff --git a/third_party/blink/public/mojom/page/page.mojom b/third_party/blink/public/mojom/page/page.mojom
-index e7be05ec6dc5f517b4a6f849a262d12dc6c1ca3d..5f4f425c77c8aadf269edfaec658a8d2ad74b2cd 100644
+index fb846303b126c0bbaa252b8b6c5b9b2971100c62..e6dcf94dcde8515e9cf73656d6c1659492aac4b4 100644
 --- a/third_party/blink/public/mojom/page/page.mojom
 +++ b/third_party/blink/public/mojom/page/page.mojom
-@@ -182,4 +182,7 @@ interface PageBroadcast {
+@@ -186,4 +186,7 @@ interface PageBroadcast {
-   // the noise token at ReadyToCommit time and update blink::WebViews that
+   // Indicates that the page's main frame should collect draggable regions set
-   // were made at request time.
+   // using the app-region CSS property.
-   UpdateCanvasNoiseToken(blink.mojom.NoiseToken? canvas_noise_token);
+   SetSupportsDraggableRegions(bool supports_draggable_regions);
 +
 +  // Whether to enable the Renderer scheduler background throttling.
 +  SetSchedulerThrottling(bool allowed);
  };
 diff --git a/third_party/blink/public/web/web_view.h b/third_party/blink/public/web/web_view.h
-index 9c0fe6ad62872f05cfb1179b4b979139008976d2..6aca43e61ef7f1caea74c30e5c3ce4496d4c4188 100644
+index 11a31c9ed26b5abde0ea812eae6b219340ed711c..a72cf76b820cb86b9495ea147efbdcf53b8a9845 100644
 --- a/third_party/blink/public/web/web_view.h
 +++ b/third_party/blink/public/web/web_view.h
 @@ -366,6 +366,7 @@ class BLINK_EXPORT WebView {
@@ -155,7 +155,7 @@ index 071ede882b2503e22ff97967a7f9cbfd96d048bd..baf06a06756ac7cdcd7f7aef15f812d5
    // Do not throttle if the page should be painting.
    bool is_visible =
 diff --git a/third_party/blink/renderer/core/exported/web_view_impl.h b/third_party/blink/renderer/core/exported/web_view_impl.h
-index 83e4be6692496d1d05dcd4110009c68763683128..f8deed2f22387c5dcc35d93c7b45ba54a77625e5 100644
+index 9b9dd237525793b149f1e79d26e9e8043131c363..ec1d8054289b1ae6eb5a579fc82b90a92fe438ff 100644
 --- a/third_party/blink/renderer/core/exported/web_view_impl.h
 +++ b/third_party/blink/renderer/core/exported/web_view_impl.h
 @@ -452,6 +452,7 @@ class CORE_EXPORT WebViewImpl final : public WebView,

patches/chromium/build_do_not_depend_on_packed_resource_integrity.patch

@@ -33,10 +33,10 @@ index e7ee2d88b136be97e0668874a309085554041a5a..1ed28fa85bf906bea9628da146627067
          "//base",
          "//build:branding_buildflags",
 diff --git a/chrome/browser/BUILD.gn b/chrome/browser/BUILD.gn
-index 7ad4a62c8bfb97d36fbd86a08d5deccdc77da129..0e281fc366c4ee35efdec3625425f2fc8ced135a 100644
+index 03767f1fa536107112eee7106323238caeeedf2c..0df5df319e4d84daed9d9017691950579fce7ae3 100644
 --- a/chrome/browser/BUILD.gn
 +++ b/chrome/browser/BUILD.gn
-@@ -4813,7 +4813,7 @@ static_library("browser") {
+@@ -4811,7 +4811,7 @@ static_library("browser") {
        ]
      }
  
@@ -46,10 +46,10 @@ index 7ad4a62c8bfb97d36fbd86a08d5deccdc77da129..0e281fc366c4ee35efdec3625425f2fc
        # than here in :chrome_dll.
        deps += [ "//chrome:packed_resources_integrity_header" ]
 diff --git a/chrome/test/BUILD.gn b/chrome/test/BUILD.gn
-index 5befc9056f87e389a296ebf2bbbc6faad96d0b67..76f632121c7a6f3582cdcbbb076df979be749cb8 100644
+index 932793506ca9259d6c4f67f6e2bbbd654b2c7be3..eff32d19f785d871e9ec9a63fe52151ee485dc1e 100644
 --- a/chrome/test/BUILD.gn
 +++ b/chrome/test/BUILD.gn
-@@ -7557,9 +7557,12 @@ test("unit_tests") {
+@@ -7563,9 +7563,12 @@ test("unit_tests") {
        "//chrome/notification_helper",
      ]
  
@@ -63,7 +63,7 @@ index 5befc9056f87e389a296ebf2bbbc6faad96d0b67..76f632121c7a6f3582cdcbbb076df979
        "//chrome//services/util_win:unit_tests",
        "//chrome/app:chrome_dll_resources",
        "//chrome/app:win_unit_tests",
-@@ -8493,6 +8496,10 @@ test("unit_tests") {
+@@ -8499,6 +8502,10 @@ test("unit_tests") {
        "../browser/performance_manager/policies/background_tab_loading_policy_unittest.cc",
      ]
  
@@ -74,7 +74,7 @@ index 5befc9056f87e389a296ebf2bbbc6faad96d0b67..76f632121c7a6f3582cdcbbb076df979
      sources += [
        # The importer code is not used on Android.
        "../common/importer/firefox_importer_utils_unittest.cc",
-@@ -8549,7 +8556,6 @@ test("unit_tests") {
+@@ -8555,7 +8562,6 @@ test("unit_tests") {
      # TODO(crbug.com/417513088): Maybe merge with the non-android `deps` declaration above?
      deps += [
        "../browser/screen_ai:screen_ai_install_state",

patches/chromium/can_create_window.patch

@@ -9,10 +9,10 @@ potentially prevent a window from being created.
 TODO(loc): this patch is currently broken.
 
 diff --git a/content/browser/renderer_host/render_frame_host_impl.cc b/content/browser/renderer_host/render_frame_host_impl.cc
-index e2a33a8275974c726148b73aae61ed23fa524a31..6635ed3b341ffc63d80d895dc5746c79092f53ab 100644
+index 55ba21754555cccb095707d30fcefeaf15ea13c6..e76cccefbbf77fcfb886c41d501bcff4fd27be2f 100644
 --- a/content/browser/renderer_host/render_frame_host_impl.cc
 +++ b/content/browser/renderer_host/render_frame_host_impl.cc
-@@ -9854,6 +9854,7 @@ void RenderFrameHostImpl::CreateNewWindow(
+@@ -9861,6 +9861,7 @@ void RenderFrameHostImpl::CreateNewWindow(
            last_committed_origin_, params->window_container_type,
            params->target_url, params->referrer.To<Referrer>(),
            params->frame_name, params->disposition, *params->features,
@@ -21,10 +21,10 @@ index e2a33a8275974c726148b73aae61ed23fa524a31..6635ed3b341ffc63d80d895dc5746c79
            &no_javascript_access);
  
 diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
-index cd6abd23d61ea7f12ac4caf9f9c5d5c1822c6c05..4472f8020547631c921860a07637c110c1d8f080 100644
+index 49d18f7595e463cc98c888a942f837757a27a596..a7ea73a46936ab4f82880121767376383864959b 100644
 --- a/content/browser/web_contents/web_contents_impl.cc
 +++ b/content/browser/web_contents/web_contents_impl.cc
-@@ -5338,6 +5338,10 @@ FrameTree* WebContentsImpl::CreateNewWindow(
+@@ -5350,6 +5350,10 @@ FrameTree* WebContentsImpl::CreateNewWindow(
    create_params.initially_hidden = renderer_started_hidden;
    create_params.initial_popup_url = params.target_url;
  
@@ -35,7 +35,7 @@ index cd6abd23d61ea7f12ac4caf9f9c5d5c1822c6c05..4472f8020547631c921860a07637c110
    // Even though all codepaths leading here are in response to a renderer
    // trying to open a new window, if the new window ends up in a different
    // browsing instance, then the RenderViewHost, RenderWidgetHost,
-@@ -5392,6 +5396,12 @@ FrameTree* WebContentsImpl::CreateNewWindow(
+@@ -5404,6 +5408,12 @@ FrameTree* WebContentsImpl::CreateNewWindow(
    // Sets the newly created WebContents WindowOpenDisposition.
    new_contents_impl->original_window_open_disposition_ = params.disposition;
  
@@ -48,7 +48,7 @@ index cd6abd23d61ea7f12ac4caf9f9c5d5c1822c6c05..4472f8020547631c921860a07637c110
    // If the new frame has a name, make sure any SiteInstances that can find
    // this named frame have proxies for it.  Must be called after
    // SetSessionStorageNamespace, since this calls CreateRenderView, which uses
-@@ -5433,12 +5443,6 @@ FrameTree* WebContentsImpl::CreateNewWindow(
+@@ -5445,12 +5455,6 @@ FrameTree* WebContentsImpl::CreateNewWindow(
      AddWebContentsDestructionObserver(new_contents_impl);
    }
  

patches/chromium/chore_expose_isolate_parameter_in_script_lifecycle_observers.patch

@@ -52,10 +52,10 @@ index 99d368046177dd92c8b36743f461d348bbf19a2e..b0a1859d22063cf6d5a73b5ccd5ea6fb
  
  void RenderFrameImpl::DidChangeScrollOffset() {
 diff --git a/content/renderer/render_frame_impl.h b/content/renderer/render_frame_impl.h
-index 542eddb03c98eac5c03c9bc208af2c863d552b2d..e91c0f20d4e401a43936a9de9b6a6b6c1199612c 100644
+index 61d4ef338cc4c0e99c144d6d95bbe0adba9d3556..ce7ba31d2a2ebab213be4b123f6af93c99b74149 100644
 --- a/content/renderer/render_frame_impl.h
 +++ b/content/renderer/render_frame_impl.h
-@@ -606,7 +606,8 @@ class CONTENT_EXPORT RenderFrameImpl
+@@ -605,7 +605,8 @@ class CONTENT_EXPORT RenderFrameImpl
                                int world_id) override;
    void DidInstallConditionalFeatures(v8::Local<v8::Context> context,
                                       int world_id) override;

patches/chromium/chore_modify_chromium_handling_of_mouse_events.patch

@@ -34,10 +34,10 @@ index 2dc44d4787d5198cff7be2cf98ad5acf2d3a9a0b..27a0335aac2bd4239616cf71f5d015c9
  
  class ScrollEvent;
 diff --git a/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc b/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc
-index d2651f4fcbb7991e9ec8f164e5bee51dab405c5a..d58b59288d881a2d74ea357f1e9e27870d24ac72 100644
+index 5dd2b9b0897131897596e88e74701293c69e012d..89287b68398e9121959e7750644d37072e8e489b 100644
 --- a/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc
 +++ b/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc
-@@ -1378,6 +1378,10 @@ HBRUSH DesktopWindowTreeHostWin::GetBackgroundPaintBrush() {
+@@ -1382,6 +1382,10 @@ HBRUSH DesktopWindowTreeHostWin::GetBackgroundPaintBrush() {
    return background_paint_brush_;
  }
  
@@ -49,10 +49,10 @@ index d2651f4fcbb7991e9ec8f164e5bee51dab405c5a..d58b59288d881a2d74ea357f1e9e2787
  DesktopWindowTreeHostWin::GetSingletonDesktopNativeCursorManager() {
    return new DesktopNativeCursorManagerWin();
 diff --git a/ui/views/widget/desktop_aura/desktop_window_tree_host_win.h b/ui/views/widget/desktop_aura/desktop_window_tree_host_win.h
-index b65ced55f997d5064b9d9338190567f8c264fce8..e8acd2828ed05deefa335ce2bb461f0c3be8d7b7 100644
+index 8b34b44095ba7884947d5e83da847783126b3e62..1e30bce5ca5bf47726fd846f2f26705d52a8ce57 100644
 --- a/ui/views/widget/desktop_aura/desktop_window_tree_host_win.h
 +++ b/ui/views/widget/desktop_aura/desktop_window_tree_host_win.h
-@@ -273,6 +273,7 @@ class VIEWS_EXPORT DesktopWindowTreeHostWin
+@@ -274,6 +274,7 @@ class VIEWS_EXPORT DesktopWindowTreeHostWin
    void HandleWindowScaleFactorChanged(float window_scale_factor) override;
    void HandleHeadlessWindowBoundsChanged(const gfx::Rect& bounds) override;
    HBRUSH GetBackgroundPaintBrush() override;

patches/chromium/chore_partial_revert_of.patch

@@ -14,10 +14,10 @@ track down the source of this problem & figure out if we can fix it
 by changing something in Electron.
 
 diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
-index 0d2e6fb394799980c61c0855d4cb4c1933719a6e..8f7467af5365f7ea0a76027256748d62b6cb7531 100644
+index 2636b49a902570bf3b92675db7792893fcc949f9..b489867c2567739ac200cd1e4c4863b3a0aa8235 100644
 --- a/content/browser/web_contents/web_contents_impl.cc
 +++ b/content/browser/web_contents/web_contents_impl.cc
-@@ -5309,7 +5309,7 @@ FrameTree* WebContentsImpl::CreateNewWindow(
+@@ -5321,7 +5321,7 @@ FrameTree* WebContentsImpl::CreateNewWindow(
            : IsGuest();
    // While some guest types do not have a guest SiteInstance, the ones that
    // don't all override WebContents creation above.

patches/chromium/chore_patch_out_profile_methods.patch

@@ -84,7 +84,7 @@ index bc0bad82ebcdceadc505e912ff27202b452fefab..6b77c57fccc4619a1df3b4ed661d2bdd
  
  ProfileSelection ProfileSelections::GetProfileSelection(
 diff --git a/chrome/browser/spellchecker/spellcheck_service.cc b/chrome/browser/spellchecker/spellcheck_service.cc
-index 4c52386f9ddf13f1453903cda3954b6c596028f2..8fbb2025d157e58c90c701f9e3478f6c99b88aa1 100644
+index eba2400655be58628ad1dbf37692a963cc031bf8..02da80b42f936f347c9043f4499d9a324bdf43d2 100644
 --- a/chrome/browser/spellchecker/spellcheck_service.cc
 +++ b/chrome/browser/spellchecker/spellcheck_service.cc
 @@ -21,8 +21,10 @@

patches/chromium/chore_provide_iswebcontentscreationoverridden_with_full_params.patch

@@ -80,10 +80,10 @@ index 39fa45f0a0f9076bd7ac0be6f455dd540a276512..3d0381d463eed73470b28085830f2a23
        content::WebContents* source,
        const content::OpenURLParams& params,
 diff --git a/chrome/browser/ui/browser.cc b/chrome/browser/ui/browser.cc
-index a66f503e1ffcf5c7435d3bfa5b8af6eda707f125..9af4329932a838c05a3ef7aa5f5da884a501c342 100644
+index 78a55026a56c5c2846c7cf13a6080456f8022ddc..f507a45212491b46954e1e30f8fc8c525aff0b25 100644
 --- a/chrome/browser/ui/browser.cc
 +++ b/chrome/browser/ui/browser.cc
-@@ -2373,7 +2373,8 @@ bool Browser::IsWebContentsCreationOverridden(
+@@ -2378,7 +2378,8 @@ bool Browser::IsWebContentsCreationOverridden(
      content::mojom::WindowContainerType window_container_type,
      const GURL& opener_url,
      const std::string& frame_name,
@@ -93,7 +93,7 @@ index a66f503e1ffcf5c7435d3bfa5b8af6eda707f125..9af4329932a838c05a3ef7aa5f5da884
    if (HasActorTask(profile(), opener)) {
      // If an ExecutionEngine is acting on the opener, prevent it from creating a
      // new WebContents. We'll instead force the navigation to happen in the same
-@@ -2386,7 +2387,7 @@ bool Browser::IsWebContentsCreationOverridden(
+@@ -2391,7 +2392,7 @@ bool Browser::IsWebContentsCreationOverridden(
    return (window_container_type ==
                content::mojom::WindowContainerType::BACKGROUND &&
            ShouldCreateBackgroundContents(source_site_instance, opener_url,
@@ -103,7 +103,7 @@ index a66f503e1ffcf5c7435d3bfa5b8af6eda707f125..9af4329932a838c05a3ef7aa5f5da884
  
  WebContents* Browser::CreateCustomWebContents(
 diff --git a/chrome/browser/ui/browser.h b/chrome/browser/ui/browser.h
-index 370f70ca0cce817fa396b284f95cda3e814eeed0..bcc9b602d361df1307a7d4a67315900a167a716d 100644
+index 12b5a5ca3603b815182621f81827635667528ca0..0bfd322dd59de0247a7e8bd09b462b943e206f3c 100644
 --- a/chrome/browser/ui/browser.h
 +++ b/chrome/browser/ui/browser.h
 @@ -943,8 +943,7 @@ class Browser : public TabStripModelObserver,
@@ -222,10 +222,10 @@ index b969f1d97b7e3396119b579cfbe61e19ff7d2dd4..b8d6169652da28266a514938b45b39c5
    content::WebContents* AddNewContents(
        content::WebContents* source,
 diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
-index 3897ca794fd23f337b73c7305b37da7a97f9c550..2451f06b6b6dc96da44494da1db5e1f47654dad4 100644
+index 6efc40408fb64d4e4c4e6671b606912edc013a41..35fe43c6ac99666d070036f7d862529ad364a359 100644
 --- a/content/browser/web_contents/web_contents_impl.cc
 +++ b/content/browser/web_contents/web_contents_impl.cc
-@@ -5272,8 +5272,7 @@ FrameTree* WebContentsImpl::CreateNewWindow(
+@@ -5284,8 +5284,7 @@ FrameTree* WebContentsImpl::CreateNewWindow(
    if (delegate_ &&
        delegate_->IsWebContentsCreationOverridden(
            opener, source_site_instance, params.window_container_type,

patches/chromium/disable_hidden.patch

@@ -34,10 +34,10 @@ index 2d32d91eb98fe749ae262ba06a1a399813aa7bab..8ebf542046ffba6823804b797e373c80
    // |routing_id| must not be IPC::mojom::kRoutingIdNone.
    // If this object outlives |delegate|, DetachDelegate() must be called when
 diff --git a/content/browser/renderer_host/render_widget_host_view_aura.cc b/content/browser/renderer_host/render_widget_host_view_aura.cc
-index e5eb88eaed395182081a387fee2a13c3b60adf23..08fc2be8e60d16de952ca7f76701ca4eea722c4b 100644
+index 816bb7c6f1c00c121f66e67d20d709008c33f02f..d97cbb4fd8e12bcbff19bf8cc8378997110c60c0 100644
 --- a/content/browser/renderer_host/render_widget_host_view_aura.cc
 +++ b/content/browser/renderer_host/render_widget_host_view_aura.cc
-@@ -642,7 +642,7 @@ void RenderWidgetHostViewAura::HideImpl() {
+@@ -696,7 +696,7 @@ void RenderWidgetHostViewAura::HideImpl() {
    CHECK(visibility_ == Visibility::HIDDEN ||
          visibility_ == Visibility::OCCLUDED);
  

patches/chromium/enable_reset_aspect_ratio.patch

@@ -6,10 +6,10 @@ Subject: feat: enable setting aspect ratio to 0
 Make SetAspectRatio accept 0 as valid input, which would reset to null.
 
 diff --git a/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc b/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc
-index 35469ecb01a680315b2f92e2599a3b56b5fc7549..d2651f4fcbb7991e9ec8f164e5bee51dab405c5a 100644
+index 55caef964e9302e939a1580494e753fac347c99e..5dd2b9b0897131897596e88e74701293c69e012d 100644
 --- a/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc
 +++ b/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc
-@@ -614,7 +614,7 @@ void DesktopWindowTreeHostWin::SetOpacity(float opacity) {
+@@ -618,7 +618,7 @@ void DesktopWindowTreeHostWin::SetOpacity(float opacity) {
  void DesktopWindowTreeHostWin::SetAspectRatio(
      const gfx::SizeF& aspect_ratio,
      const gfx::Size& excluded_margin) {

patches/chromium/feat_allow_embedders_to_add_observers_on_created_hunspell.patch

@@ -7,10 +7,10 @@ Subject: feat: allow embedders to add observers on created hunspell
 This patch is used by Electron to implement spellchecker events.
 
 diff --git a/chrome/browser/spellchecker/spellcheck_service.cc b/chrome/browser/spellchecker/spellcheck_service.cc
-index 3928d6fdbda8aac5fb89ab148adaa18218e135f8..4c52386f9ddf13f1453903cda3954b6c596028f2 100644
+index dbc05afd488118396c191c61a37692aba1fe858b..eba2400655be58628ad1dbf37692a963cc031bf8 100644
 --- a/chrome/browser/spellchecker/spellcheck_service.cc
 +++ b/chrome/browser/spellchecker/spellcheck_service.cc
-@@ -478,6 +478,8 @@ void SpellcheckService::LoadDictionaries() {
+@@ -476,6 +476,8 @@ void SpellcheckService::LoadDictionaries() {
          std::make_unique<SpellcheckHunspellDictionary>(
              dictionary, platform_spellcheck_language, context_, this));
      hunspell_dictionaries_.back()->AddObserver(this);
@@ -19,7 +19,7 @@ index 3928d6fdbda8aac5fb89ab148adaa18218e135f8..4c52386f9ddf13f1453903cda3954b6c
      hunspell_dictionaries_.back()->Load();
    }
  
-@@ -532,6 +534,20 @@ bool SpellcheckService::IsSpellcheckEnabled() const {
+@@ -526,6 +528,20 @@ bool SpellcheckService::IsSpellcheckEnabled() const {
           (!hunspell_dictionaries_.empty() || enable_if_uninitialized);
  }
  

patches/chromium/feat_corner_smoothing_css_rule_and_blink_painting.patch

@@ -45,10 +45,10 @@ index e189d584f05f2ce6354c03a9b19f56985df8a15e..41b430e8f2416be098494f5c49fb97ca
                      'internal-forced-visited-'):
                  internal_visited_order = 0
 diff --git a/third_party/blink/renderer/core/css/css_properties.json5 b/third_party/blink/renderer/core/css/css_properties.json5
-index 5e4e2becfabf4a85d9253b590ecc86297aa37ce4..a916e3dd149f33ad2a98d031303a38f9c673c9b8 100644
+index 122347f812e07a1843914b2c160922433712b7c8..3a619b6e6a970609431ecf67801c05f1d401e807 100644
 --- a/third_party/blink/renderer/core/css/css_properties.json5
 +++ b/third_party/blink/renderer/core/css/css_properties.json5
-@@ -9040,6 +9040,26 @@
+@@ -9036,6 +9036,26 @@
        property_methods: ["ParseShorthand", "CSSValueFromComputedStyleInternal"],
      },
  
@@ -312,7 +312,7 @@ index 1d6b8160e8db2a94ee61ed41ac9a74db5b1bfb17..373bcd30c6a4526262912021aaf2b560
  
    auto DrawAsSinglePath = [&]() {
 diff --git a/third_party/blink/renderer/platform/runtime_enabled_features.json5 b/third_party/blink/renderer/platform/runtime_enabled_features.json5
-index c5c94ad6f34aa3bd060224ae01ccc705354e5158..0331b41978697787c0ea2cf6360ac9d2b5ed85a1 100644
+index 34c13ec5ff7ed98c9472abb5840c164a5ce5456d..3fe2753c8bba305a51fa5992e7ff9f1e2daf1e0c 100644
 --- a/third_party/blink/renderer/platform/runtime_enabled_features.json5
 +++ b/third_party/blink/renderer/platform/runtime_enabled_features.json5
 @@ -214,6 +214,10 @@

patches/chromium/fix_adjust_headless_mode_handling_in_native_widget.patch

@@ -19,7 +19,7 @@ https://chromium-review.googlesource.com/c/chromium/src/+/6936895
 as we depend on the removed functionality in this patch.
 
 diff --git a/components/remote_cocoa/app_shim/native_widget_ns_window_bridge.mm b/components/remote_cocoa/app_shim/native_widget_ns_window_bridge.mm
-index f651286bc85f3640ec072b05eb2f0d118e02417a..94ee607bc9de2bf388a736c438613b51de1a5ac2 100644
+index ce52245628c72018da8ec4a3155dafa74e42c8e3..89a078d1ce00667bd83def21e341b03ca6c79ee3 100644
 --- a/components/remote_cocoa/app_shim/native_widget_ns_window_bridge.mm
 +++ b/components/remote_cocoa/app_shim/native_widget_ns_window_bridge.mm
 @@ -522,7 +522,7 @@ NSUInteger CountBridgedWindows(NSArray* child_windows) {
@@ -45,10 +45,10 @@ index 11954a3adfb6d517b6dc8e780a4a9aba8a0bf98a..1ddc1f34055c8b42177703ccc2f0d006
    // window's workspace and fullscreen state, and can be retrieved from or
    // applied to a window.
 diff --git a/ui/views/cocoa/native_widget_mac_ns_window_host.h b/ui/views/cocoa/native_widget_mac_ns_window_host.h
-index e523151fb670af28cf2c54548c5009825fdbed92..66d5724f848b328a19362a3c0f6346704ddb50ac 100644
+index 2239b085ac7fd87fe06aef1001551f8afe8e21e4..9ead3ab0755fe5c3500893325f0597e07e7241cc 100644
 --- a/ui/views/cocoa/native_widget_mac_ns_window_host.h
 +++ b/ui/views/cocoa/native_widget_mac_ns_window_host.h
-@@ -554,6 +554,7 @@ class VIEWS_EXPORT NativeWidgetMacNSWindowHost
+@@ -556,6 +556,7 @@ class VIEWS_EXPORT NativeWidgetMacNSWindowHost
    bool is_miniaturized_ = false;
    bool is_window_key_ = false;
    bool is_mouse_capture_active_ = false;
@@ -57,10 +57,10 @@ index e523151fb670af28cf2c54548c5009825fdbed92..66d5724f848b328a19362a3c0f634670
    gfx::Rect window_bounds_before_fullscreen_;
  
 diff --git a/ui/views/cocoa/native_widget_mac_ns_window_host.mm b/ui/views/cocoa/native_widget_mac_ns_window_host.mm
-index e1a1cdb2ec192d2ee5a555ecccf041f757336f79..68a210eaf34d6d410a14478ad5bf0c78faa30388 100644
+index ae113be147f5bfe9d6218a20495897600cc5299d..cb67460205f4db04a3256151d49a2713688c7627 100644
 --- a/ui/views/cocoa/native_widget_mac_ns_window_host.mm
 +++ b/ui/views/cocoa/native_widget_mac_ns_window_host.mm
-@@ -465,6 +465,7 @@ void HandleAccelerator(const ui::Accelerator& accelerator,
+@@ -467,6 +467,7 @@ void HandleAccelerator(const ui::Accelerator& accelerator,
    if (!is_tooltip) {
      tooltip_manager_ = std::make_unique<TooltipManagerMac>(GetNSWindowMojo());
    }
@@ -68,7 +68,7 @@ index e1a1cdb2ec192d2ee5a555ecccf041f757336f79..68a210eaf34d6d410a14478ad5bf0c78
  
    if (params.workspace.length()) {
      std::string restoration_data;
-@@ -482,6 +483,7 @@ void HandleAccelerator(const ui::Accelerator& accelerator,
+@@ -484,6 +485,7 @@ void HandleAccelerator(const ui::Accelerator& accelerator,
      window_params->modal_type = widget->widget_delegate()->GetModalType();
      window_params->is_translucent =
          params.opacity == Widget::InitParams::WindowOpacity::kTranslucent;
@@ -76,7 +76,7 @@ index e1a1cdb2ec192d2ee5a555ecccf041f757336f79..68a210eaf34d6d410a14478ad5bf0c78
      window_params->is_tooltip = is_tooltip;
  
      // macOS likes to put shadows on most things. However, frameless windows
-@@ -663,9 +665,10 @@ void HandleAccelerator(const ui::Accelerator& accelerator,
+@@ -665,9 +667,10 @@ void HandleAccelerator(const ui::Accelerator& accelerator,
    // case it will never become visible but we want its compositor to produce
    // frames for screenshooting and screencasting.
    UpdateCompositorProperties();
@@ -90,7 +90,7 @@ index e1a1cdb2ec192d2ee5a555ecccf041f757336f79..68a210eaf34d6d410a14478ad5bf0c78
  
    // Register the CGWindowID (used to identify this window for video capture)
 diff --git a/ui/views/widget/widget.cc b/ui/views/widget/widget.cc
-index 566acaeff6b746c97db606cbda71b29e82570453..28f14b53aa9f2daf25431231539a5dbfc3c42b95 100644
+index 45c684170a028198ec12b75dfe8f51c1271d55f6..f52d5bdfbdd108b55d7e9b2882eb8d5039ef279c 100644
 --- a/ui/views/widget/widget.cc
 +++ b/ui/views/widget/widget.cc
 @@ -222,6 +222,18 @@ ui::ZOrderLevel Widget::InitParams::EffectiveZOrderLevel() const {
@@ -121,7 +121,7 @@ index 566acaeff6b746c97db606cbda71b29e82570453..28f14b53aa9f2daf25431231539a5dbf
  
    if (params.opacity == views::Widget::InitParams::WindowOpacity::kInferred &&
 diff --git a/ui/views/widget/widget.h b/ui/views/widget/widget.h
-index ce34d038564570f4edc8e36fd29524bd93c0b462..808abf2ce1c797591304a8ece9e8a169f034273e 100644
+index e2ea4ca2fb5f10045466d2ece7e9148c01b84f29..7cd620467634d267d1c1b0806cea338edfe5837d 100644
 --- a/ui/views/widget/widget.h
 +++ b/ui/views/widget/widget.h
 @@ -324,6 +324,11 @@ class VIEWS_EXPORT Widget : public internal::NativeWidgetDelegate,
@@ -158,7 +158,7 @@ index ce34d038564570f4edc8e36fd29524bd93c0b462..808abf2ce1c797591304a8ece9e8a169
    // True if the window size will follow the content preferred size.
    bool is_autosized() const { return is_autosized_; }
  
-@@ -1715,6 +1728,9 @@ class VIEWS_EXPORT Widget : public internal::NativeWidgetDelegate,
+@@ -1716,6 +1729,9 @@ class VIEWS_EXPORT Widget : public internal::NativeWidgetDelegate,
    // If true, the mouse is currently down.
    bool is_mouse_button_pressed_ = false;
  

patches/chromium/fix_check_for_file_existence_before_setting_mtime.patch

@@ -0,0 +1,27 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Charles Kerr <charles@charleskerr.com>
+Date: Tue, 21 Oct 2025 18:44:52 -0500
+Subject: fix: check for file existence before setting mtime
+
+Check for broken links by confirming the file exists before setting its utime.
+
+This patch should be upstreamed & removed.
+
+diff --git a/tools/clang/scripts/update.py b/tools/clang/scripts/update.py
+index bcf4c9b192234aa1d470662e4036ac7a23ce2262..724ccef88dc6d798bb948d3fc89a84640d863174 100755
+--- a/tools/clang/scripts/update.py
++++ b/tools/clang/scripts/update.py
+@@ -201,10 +201,9 @@ def DownloadAndUnpack(url, output_dir, path_prefixes=None, is_known_zip=False):
+       # The nicest way to do this would be by passing a filter to extractall,
+       # but that functionality is not available in macOS system Python (3.9.6).
+       for m in members:
+-        # Confusingly, this checks if you're allowed to _not_ follow symlinks.
+-        if os.utime in os.supports_follow_symlinks:
+-          os.utime(os.path.join(output_dir, m.name), follow_symlinks=False)
+-        else:
++        # check for broken links before setting the file's utime
++        member_path = os.path.join(output_dir, m.name)
++        if os.path.exists(member_path):
+           os.utime(os.path.join(output_dir, m.name))
+ 
+ 

patches/chromium/fix_on-screen-keyboard_hides_on_input_blur_in_webview.patch

@@ -9,10 +9,10 @@ focus node change via TextInputManager.
 chromium-bug: https://crbug.com/1369605
 
 diff --git a/content/browser/renderer_host/render_widget_host_view_aura.cc b/content/browser/renderer_host/render_widget_host_view_aura.cc
-index 8ad61a86598ac2249496e44113f31ebb21dc616b..36eb119c30531faffb85c4456572f22a9735316d 100644
+index 1041d25d5ef78abdcf7b85fe8457ec2a20e2a759..f91f346c93749ff77844143b53d27d14735a6a06 100644
 --- a/content/browser/renderer_host/render_widget_host_view_aura.cc
 +++ b/content/browser/renderer_host/render_widget_host_view_aura.cc
-@@ -3248,6 +3248,12 @@ void RenderWidgetHostViewAura::OnTextSelectionChanged(
+@@ -3332,6 +3332,12 @@ void RenderWidgetHostViewAura::OnTextSelectionChanged(
    }
  }
  
@@ -26,10 +26,10 @@ index 8ad61a86598ac2249496e44113f31ebb21dc616b..36eb119c30531faffb85c4456572f22a
      RenderWidgetHostViewAura* popup_child_host_view) {
    popup_child_host_view_ = popup_child_host_view;
 diff --git a/content/browser/renderer_host/render_widget_host_view_aura.h b/content/browser/renderer_host/render_widget_host_view_aura.h
-index 943006033c5f9c6d5cfdbc50ede2723fa8494834..49eb7cb18d1fa114d78048a6e41b8883afdcf674 100644
+index da64a2093e5ab60b320a1ea2b12a920956ef9605..9f1e856d0947c3ce1f21e001c5278f61cbda05d3 100644
 --- a/content/browser/renderer_host/render_widget_host_view_aura.h
 +++ b/content/browser/renderer_host/render_widget_host_view_aura.h
-@@ -657,6 +657,8 @@ class CONTENT_EXPORT RenderWidgetHostViewAura
+@@ -664,6 +664,8 @@ class CONTENT_EXPORT RenderWidgetHostViewAura
        RenderWidgetHostViewBase* updated_view) override;
    void OnTextSelectionChanged(TextInputManager* text_input_mangager,
                                RenderWidgetHostViewBase* updated_view) override;
@@ -87,10 +87,10 @@ index 75df43e3cd2721a92c90c18154d53d5c203e2465..ce42c75c8face36d21f53f44c0201ac4
    // The view with active text input state, i.e., a focused <input> element.
    // It will be nullptr if no such view exists. Note that the active view
 diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
-index 208fe58f95557ee103555858c2cda39e732ca991..0d2e6fb394799980c61c0855d4cb4c1933719a6e 100644
+index cbfa2ec56627994541548a49a4afe33b6e42c2d7..2636b49a902570bf3b92675db7792893fcc949f9 100644
 --- a/content/browser/web_contents/web_contents_impl.cc
 +++ b/content/browser/web_contents/web_contents_impl.cc
-@@ -10143,7 +10143,7 @@ void WebContentsImpl::OnFocusedElementChangedInFrame(
+@@ -10142,7 +10142,7 @@ void WebContentsImpl::OnFocusedElementChangedInFrame(
                          "WebContentsImpl::OnFocusedElementChangedInFrame",
                          "render_frame_host", frame);
    RenderWidgetHostViewBase* root_view =

patches/chromium/fix_resolve_dynamic_background_material_update_issue_on_windows_11.patch

@@ -8,7 +8,7 @@ such as the background turning black when maximizing the window and
 dynamic background material settings not taking effect.
 
 diff --git a/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc b/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc
-index 956dc87cb07559038a63cec0b5174cec09619bdb..68635b0c0153c3464ab6c7d317177098a7ec644c 100644
+index 29bf4dfbe2cf0af5a1369c4d3e17e50a198c78c6..40a405af0ecde4f649e1fc27d7e4bf739fe0efd0 100644
 --- a/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc
 +++ b/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc
 @@ -183,6 +183,10 @@ void DesktopWindowTreeHostWin::FinishTouchDrag(gfx::Point screen_point) {
@@ -23,7 +23,7 @@ index 956dc87cb07559038a63cec0b5174cec09619bdb..68635b0c0153c3464ab6c7d317177098
  
  void DesktopWindowTreeHostWin::Init(const Widget::InitParams& params) {
 diff --git a/ui/views/widget/desktop_aura/desktop_window_tree_host_win.h b/ui/views/widget/desktop_aura/desktop_window_tree_host_win.h
-index 0cd07fd5fb55dcc0d972de4c027fcb895d156592..0f4d335e1d54b5e92fc217080d86513db94d4122 100644
+index 2529a00eb6ec30e4269f19c685997a778647bd51..c3e59f3cfefb965c39482539b06c964166e8b78e 100644
 --- a/ui/views/widget/desktop_aura/desktop_window_tree_host_win.h
 +++ b/ui/views/widget/desktop_aura/desktop_window_tree_host_win.h
 @@ -93,6 +93,8 @@ class VIEWS_EXPORT DesktopWindowTreeHostWin

patches/chromium/mas_avoid_private_macos_api_usage.patch.patch

@@ -35,7 +35,7 @@ system font by checking if it's kCTFontPriorityAttribute is set to
 system priority.
 
 diff --git a/base/BUILD.gn b/base/BUILD.gn
-index d73ee1145fa64c309eddd02c62af6ee735c62e00..99810c2a0bd3550385ca2be80e4286eb78f201c9 100644
+index e6625d8ecf9274c00fe450cc2c7c479914eb0dd6..853cbd806f2fb16ad724767b15b6c6a7f5c4a286 100644
 --- a/base/BUILD.gn
 +++ b/base/BUILD.gn
 @@ -1069,6 +1069,7 @@ component("base") {
@@ -452,7 +452,7 @@ index 433f12928857e288b6b0d4f4dd3d1f29da08cf6c..bb95aabec2e0d5c7b3a5d315c9a3f8cb
    bool shouldShowWindowTitle = YES;
    if (_bridge)
 diff --git a/components/remote_cocoa/app_shim/native_widget_ns_window_bridge.mm b/components/remote_cocoa/app_shim/native_widget_ns_window_bridge.mm
-index f9f453e713b1beff8fda2fcd2a21907640c19817..f651286bc85f3640ec072b05eb2f0d118e02417a 100644
+index f3ea2bf2d15d815a2409441a9033a92d5d8967c1..ce52245628c72018da8ec4a3155dafa74e42c8e3 100644
 --- a/components/remote_cocoa/app_shim/native_widget_ns_window_bridge.mm
 +++ b/components/remote_cocoa/app_shim/native_widget_ns_window_bridge.mm
 @@ -42,6 +42,7 @@
@@ -986,10 +986,10 @@ index 6cde211f88439af0925296b0c8c9500aecadc034..08e7053117478ea898264040eea119dc
  }  // namespace
  #endif
 diff --git a/net/dns/BUILD.gn b/net/dns/BUILD.gn
-index 4428896957be15908ce992189db2a0fe95ba3bbd..07987fad41d194bf38a6f4265ccbd853c1273689 100644
+index 5ed1605df7339b504838dfd949772b47ed72a89f..07ccbd74e0835f20edfeef76d0e5e1241a48a65c 100644
 --- a/net/dns/BUILD.gn
 +++ b/net/dns/BUILD.gn
-@@ -195,6 +195,8 @@ source_set("dns") {
+@@ -197,6 +197,8 @@ source_set("dns") {
      ":host_resolver_manager",
      ":mdns_client",
    ]
@@ -1882,7 +1882,7 @@ index dd2fcedc84417c324021e4aba4e78a84ff098803..ed3b4b5b8e9d931e7b7f9b5d91f93f5f
      sources += [
        "test/desktop_window_tree_host_win_test_api.cc",
 diff --git a/ui/views/cocoa/native_widget_mac_ns_window_host.h b/ui/views/cocoa/native_widget_mac_ns_window_host.h
-index e855d05f466059f20a31022a1a2810eeadeb4fff..e523151fb670af28cf2c54548c5009825fdbed92 100644
+index fdc7eb4e4c5e8338c725f7d317559b091d8b38fe..2239b085ac7fd87fe06aef1001551f8afe8e21e4 100644
 --- a/ui/views/cocoa/native_widget_mac_ns_window_host.h
 +++ b/ui/views/cocoa/native_widget_mac_ns_window_host.h
 @@ -19,6 +19,7 @@
@@ -1903,7 +1903,7 @@ index e855d05f466059f20a31022a1a2810eeadeb4fff..e523151fb670af28cf2c54548c500982
  @class NSView;
  
  namespace remote_cocoa {
-@@ -504,10 +507,12 @@ class VIEWS_EXPORT NativeWidgetMacNSWindowHost
+@@ -506,10 +509,12 @@ class VIEWS_EXPORT NativeWidgetMacNSWindowHost
    mojo::AssociatedRemote<remote_cocoa::mojom::NativeWidgetNSWindow>
        remote_ns_window_remote_;
  
@@ -1917,7 +1917,7 @@ index e855d05f466059f20a31022a1a2810eeadeb4fff..e523151fb670af28cf2c54548c500982
    // Used to force the NSApplication's focused accessibility element to be the
    // views::Views accessibility tree when the NSView for this is focused.
 diff --git a/ui/views/cocoa/native_widget_mac_ns_window_host.mm b/ui/views/cocoa/native_widget_mac_ns_window_host.mm
-index ac4257215c61f3cb388e14f4439e23ac29f1307d..e1a1cdb2ec192d2ee5a555ecccf041f757336f79 100644
+index 99bac834cb77f16b061c7dcf209b4f90cc6da8d8..ae113be147f5bfe9d6218a20495897600cc5299d 100644
 --- a/ui/views/cocoa/native_widget_mac_ns_window_host.mm
 +++ b/ui/views/cocoa/native_widget_mac_ns_window_host.mm
 @@ -21,6 +21,7 @@
@@ -1928,7 +1928,7 @@ index ac4257215c61f3cb388e14f4439e23ac29f1307d..e1a1cdb2ec192d2ee5a555ecccf041f7
  #include "mojo/public/cpp/bindings/self_owned_associated_receiver.h"
  #include "ui/accelerated_widget_mac/window_resize_helper_mac.h"
  #include "ui/accessibility/accessibility_features.h"
-@@ -360,8 +361,12 @@ void HandleAccelerator(const ui::Accelerator& accelerator,
+@@ -362,8 +363,12 @@ void HandleAccelerator(const ui::Accelerator& accelerator,
    if (in_process_ns_window_bridge_) {
      return gfx::NativeViewAccessible(in_process_ns_window_bridge_->ns_view());
    }
@@ -1941,7 +1941,7 @@ index ac4257215c61f3cb388e14f4439e23ac29f1307d..e1a1cdb2ec192d2ee5a555ecccf041f7
  }
  
  gfx::NativeViewAccessible
-@@ -377,8 +382,12 @@ void HandleAccelerator(const ui::Accelerator& accelerator,
+@@ -379,8 +384,12 @@ void HandleAccelerator(const ui::Accelerator& accelerator,
          [in_process_ns_window_bridge_->ns_view() window]);
    }
  
@@ -1954,7 +1954,7 @@ index ac4257215c61f3cb388e14f4439e23ac29f1307d..e1a1cdb2ec192d2ee5a555ecccf041f7
  }
  
  remote_cocoa::mojom::NativeWidgetNSWindow*
-@@ -1445,9 +1454,11 @@ void HandleAccelerator(const ui::Accelerator& accelerator,
+@@ -1447,9 +1456,11 @@ void HandleAccelerator(const ui::Accelerator& accelerator,
    // for PWAs. However this breaks accessibility on in-process windows,
    // so set it back to NO when a local window gains focus. See
    // https://crbug.com/41485830.
@@ -1966,7 +1966,7 @@ index ac4257215c61f3cb388e14f4439e23ac29f1307d..e1a1cdb2ec192d2ee5a555ecccf041f7
    // Explicitly set the keyboard accessibility state on regaining key
    // window status.
    if (is_key && is_content_first_responder) {
-@@ -1588,17 +1599,20 @@ void HandleAccelerator(const ui::Accelerator& accelerator,
+@@ -1602,17 +1613,20 @@ void HandleAccelerator(const ui::Accelerator& accelerator,
  void NativeWidgetMacNSWindowHost::SetRemoteAccessibilityTokens(
      const std::vector<uint8_t>& window_token,
      const std::vector<uint8_t>& view_token) {
@@ -1987,7 +1987,7 @@ index ac4257215c61f3cb388e14f4439e23ac29f1307d..e1a1cdb2ec192d2ee5a555ecccf041f7
    *pid = getpid();
    id element_id = GetNativeViewAccessible();
  
-@@ -1611,6 +1625,7 @@ void HandleAccelerator(const ui::Accelerator& accelerator,
+@@ -1625,6 +1639,7 @@ void HandleAccelerator(const ui::Accelerator& accelerator,
    }
  
    *token = ui::RemoteAccessibility::GetTokenForLocalElement(element_id);

patches/chromium/notification_provenance.patch

@@ -133,7 +133,7 @@ index 5be62a3fb27e37f3c1db6b811172f6dfebe18f61..34349f9832fe4b9a3d48db613a789afb
        const GURL& document_url,
        const WeakDocumentPtr& weak_document_ptr,
 diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
-index 659d42adfea710b9ff9e315cffa6268a61d68243..e4df51e2fac09cd2c97bb125b9187aede4138f23 100644
+index d689ab09609595e9738a771d723f2923f629d6cb..ae46fafbb67668d3c0a147cb0d8cf8fda958409a 100644
 --- a/content/browser/renderer_host/render_process_host_impl.cc
 +++ b/content/browser/renderer_host/render_process_host_impl.cc
 @@ -2314,7 +2314,7 @@ void RenderProcessHostImpl::CreateNotificationService(

patches/chromium/refactor_expose_cursor_changes_to_the_webcontentsobserver.patch

@@ -44,10 +44,10 @@ index 3a820b1b9c9aab336c724ef8c0d823eddb330e1e..9a24c153e47b3f3878fa6ea92fb99d14
  
  void RenderWidgetHostImpl::ShowContextMenuAtPoint(
 diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
-index 4472f8020547631c921860a07637c110c1d8f080..3897ca794fd23f337b73c7305b37da7a97f9c550 100644
+index a7ea73a46936ab4f82880121767376383864959b..6efc40408fb64d4e4c4e6671b606912edc013a41 100644
 --- a/content/browser/web_contents/web_contents_impl.cc
 +++ b/content/browser/web_contents/web_contents_impl.cc
-@@ -6149,6 +6149,11 @@ TextInputManager* WebContentsImpl::GetTextInputManager() {
+@@ -6161,6 +6161,11 @@ TextInputManager* WebContentsImpl::GetTextInputManager() {
    return text_input_manager_.get();
  }
  
@@ -60,10 +60,10 @@ index 4472f8020547631c921860a07637c110c1d8f080..3897ca794fd23f337b73c7305b37da7a
      RenderWidgetHostImpl* render_widget_host) {
    return render_widget_host == GetPrimaryMainFrame()->GetRenderWidgetHost();
 diff --git a/content/browser/web_contents/web_contents_impl.h b/content/browser/web_contents/web_contents_impl.h
-index 8e26b26988f910aefd3775f56b024f3fae331fce..247e71fa9a43116b40cfffd8da0169223272d9c9 100644
+index 82c714ebe0e18cd7715e028836c396c214283d24..9b065992fc577084ef16aaef1436fd0855e32981 100644
 --- a/content/browser/web_contents/web_contents_impl.h
 +++ b/content/browser/web_contents/web_contents_impl.h
-@@ -1176,6 +1176,7 @@ class CONTENT_EXPORT WebContentsImpl
+@@ -1183,6 +1183,7 @@ class CONTENT_EXPORT WebContentsImpl
    void SendScreenRects() override;
    void SendActiveState(bool active) override;
    TextInputManager* GetTextInputManager() override;
@@ -72,10 +72,10 @@ index 8e26b26988f910aefd3775f56b024f3fae331fce..247e71fa9a43116b40cfffd8da016922
        RenderWidgetHostImpl* render_widget_host) override;
    bool IsShowingContextMenuOnPage() const override;
 diff --git a/content/public/browser/web_contents_observer.h b/content/public/browser/web_contents_observer.h
-index 4faff4e44a441cd9e95ee926d6e62a9249424433..bf06dcb8b69001f914541423824a144ac331f190 100644
+index 8e0a8b0e3e005d81c7fec493eca9e8262edb2853..1fb13e811d5ee2875b6c4162c6b9843d3e59d431 100644
 --- a/content/public/browser/web_contents_observer.h
 +++ b/content/public/browser/web_contents_observer.h
-@@ -34,6 +34,7 @@
+@@ -33,6 +33,7 @@
  #include "third_party/blink/public/mojom/frame/viewport_intersection_state.mojom-forward.h"
  #include "third_party/blink/public/mojom/loader/resource_load_info.mojom-forward.h"
  #include "third_party/blink/public/mojom/media/capture_handle_config.mojom-forward.h"
@@ -83,7 +83,7 @@ index 4faff4e44a441cd9e95ee926d6e62a9249424433..bf06dcb8b69001f914541423824a144a
  #include "ui/base/page_transition_types.h"
  #include "ui/base/window_open_disposition.h"
  
-@@ -642,6 +643,9 @@ class CONTENT_EXPORT WebContentsObserver : public base::CheckedObserver {
+@@ -641,6 +642,9 @@ class CONTENT_EXPORT WebContentsObserver : public base::CheckedObserver {
    // Invoked when the primary main frame changes size.
    virtual void PrimaryMainFrameWasResized(bool width_changed) {}
  

patches/chromium/refactor_unfilter_unresponsive_events.patch

@@ -15,10 +15,10 @@ This CL removes these filters so the unresponsive event can still be
 accessed from our JS event. The filtering is moved into Electron's code.
 
 diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
-index 8f7467af5365f7ea0a76027256748d62b6cb7531..a9813ead175b478227bb91daf0d23cffc1bedca6 100644
+index b489867c2567739ac200cd1e4c4863b3a0aa8235..6edd4d673dd61b396aaf121ff3e6810fd0b4ba00 100644
 --- a/content/browser/web_contents/web_contents_impl.cc
 +++ b/content/browser/web_contents/web_contents_impl.cc
-@@ -10281,25 +10281,13 @@ void WebContentsImpl::RendererUnresponsive(
+@@ -10291,25 +10291,13 @@ void WebContentsImpl::RendererUnresponsive(
      base::RepeatingClosure hang_monitor_restarter) {
    OPTIONAL_TRACE_EVENT1("content", "WebContentsImpl::RendererUnresponsive",
                          "render_widget_host", render_widget_host);

patches/chromium/revert_cleanup_remove_feature_windelayspellcheckserviceinit.patch

@@ -0,0 +1,765 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Charles Kerr <charles@charleskerr.com>
+Date: Tue, 21 Oct 2025 21:45:33 -0500
+Subject: Revert "[cleanup] Remove feature WinDelaySpellcheckServiceInit"
+
+This reverts commit 5fe1e59226f59c4d6fb70e7410d1a0ab83688ae2.
+
+Our codebase currently needs the ability to delay this service.
+It was added in c2d7164 (#38248) to fix a crash originally
+described in 97b353a (#34993):
+
+> Delaying spell check initialization is causing specs for
+> 'custom dictionary word list API' to fail in Electron.
+
+This patch can be removed when we fix that crash.
+
+diff --git a/chrome/browser/chrome_browser_main.cc b/chrome/browser/chrome_browser_main.cc
+index 9cb826530cf567e98baf91a60ca1f7496aca9431..2d0e92f9f373f8ef6ffa3c292811df957d457c95 100644
+--- a/chrome/browser/chrome_browser_main.cc
++++ b/chrome/browser/chrome_browser_main.cc
+@@ -1412,6 +1412,17 @@ void ChromeBrowserMainParts::PostProfileInit(Profile* profile,
+                        profile->GetPath()));
+   }
+ 
++#if BUILDFLAG(USE_BROWSER_SPELLCHECKER)
++  // Create the spellcheck service. This will asynchronously retrieve the
++  // Windows platform spellcheck dictionary language tags used to populate the
++  // context menu for editable content.
++  if (spellcheck::UseBrowserSpellChecker() &&
++      profile->GetPrefs()->GetBoolean(spellcheck::prefs::kSpellCheckEnable) &&
++      !base::FeatureList::IsEnabled(
++          spellcheck::kWinDelaySpellcheckServiceInit)) {
++    SpellcheckServiceFactory::GetForContext(profile);
++  }
++#endif
+ #endif  // BUILDFLAG(IS_WIN)
+ 
+ #if BUILDFLAG(IS_ANDROID) || BUILDFLAG(IS_CHROMEOS) || BUILDFLAG(IS_LINUX) || \
+diff --git a/chrome/browser/extensions/api/language_settings_private/language_settings_private_api.cc b/chrome/browser/extensions/api/language_settings_private/language_settings_private_api.cc
+index 5bad748fdfc7944a44dbe4dd7891eda31e3128d3..c1701b71a76695c3e941009bdd55777167907834 100644
+--- a/chrome/browser/extensions/api/language_settings_private/language_settings_private_api.cc
++++ b/chrome/browser/extensions/api/language_settings_private/language_settings_private_api.cc
+@@ -275,15 +275,21 @@ LanguageSettingsPrivateGetLanguageListFunction::Run() {
+ 
+ #if BUILDFLAG(IS_WIN)
+   if (spellcheck::UseBrowserSpellChecker()) {
+-    // Asynchronously load the dictionaries to determine platform support.
+-    SpellcheckService* service =
+-        SpellcheckServiceFactory::GetForContext(browser_context());
+-    AddRef();  // Balanced in OnDictionariesInitialized
+-    service->InitializeDictionaries(
+-        base::BindOnce(&LanguageSettingsPrivateGetLanguageListFunction::
+-                           OnDictionariesInitialized,
+-                       base::Unretained(this)));
+-    return RespondLater();
++    if (!base::FeatureList::IsEnabled(
++            spellcheck::kWinDelaySpellcheckServiceInit)) {
++      // Platform dictionary support already determined at browser startup.
++      UpdateSupportedPlatformDictionaries();
++    } else {
++      // Asynchronously load the dictionaries to determine platform support.
++      SpellcheckService* service =
++          SpellcheckServiceFactory::GetForContext(browser_context());
++      AddRef();  // Balanced in OnDictionariesInitialized
++      service->InitializeDictionaries(
++          base::BindOnce(&LanguageSettingsPrivateGetLanguageListFunction::
++                             OnDictionariesInitialized,
++                         base::Unretained(this)));
++      return RespondLater();
++    }
+   }
+ #endif  // BUILDFLAG(IS_WIN)
+ 
+diff --git a/chrome/browser/extensions/api/language_settings_private/language_settings_private_api_unittest.cc b/chrome/browser/extensions/api/language_settings_private/language_settings_private_api_unittest.cc
+index 272d50c9b060a8984a15d2dfbf2297e931482b57..e74b37ed7e596ea57728694eab9a398e94bde08c 100644
+--- a/chrome/browser/extensions/api/language_settings_private/language_settings_private_api_unittest.cc
++++ b/chrome/browser/extensions/api/language_settings_private/language_settings_private_api_unittest.cc
+@@ -116,6 +116,8 @@ class LanguageSettingsPrivateApiTest : public ExtensionServiceTestBase {
+  protected:
+   void RunGetLanguageListTest();
+ 
++  virtual void InitFeatures() {}
++
+ #if BUILDFLAG(IS_WIN)
+   virtual void AddSpellcheckLanguagesForTesting(
+       const std::vector<std::string>& spellcheck_languages_for_testing) {
+@@ -134,6 +136,8 @@ class LanguageSettingsPrivateApiTest : public ExtensionServiceTestBase {
+     EventRouterFactory::GetInstance()->SetTestingFactory(
+         profile(), base::BindRepeating(&BuildEventRouter));
+ 
++    InitFeatures();
++
+     LanguageSettingsPrivateDelegateFactory::GetInstance()->SetTestingFactory(
+         profile(), base::BindRepeating(&BuildLanguageSettingsPrivateDelegate));
+ 
+@@ -291,6 +295,28 @@ TEST_F(LanguageSettingsPrivateApiTest, GetNeverTranslateLanguagesListTest) {
+   }
+ }
+ 
++class LanguageSettingsPrivateApiGetLanguageListTest
++    : public LanguageSettingsPrivateApiTest {
++ public:
++  LanguageSettingsPrivateApiGetLanguageListTest() = default;
++  ~LanguageSettingsPrivateApiGetLanguageListTest() override = default;
++
++ protected:
++  void InitFeatures() override {
++#if BUILDFLAG(IS_WIN)
++    // Disable the delayed init feature since that case is tested in
++    // LanguageSettingsPrivateApiTestDelayInit below.
++    feature_list_.InitAndDisableFeature(
++        spellcheck::kWinDelaySpellcheckServiceInit);
++#endif  // BUILDFLAG(IS_WIN)
++  }
++};
++
++TEST_F(LanguageSettingsPrivateApiGetLanguageListTest, GetLanguageList) {
++  translate::TranslateDownloadManager::GetInstance()->ResetForTesting();
++  RunGetLanguageListTest();
++}
++
+ void LanguageSettingsPrivateApiTest::RunGetLanguageListTest() {
+   struct LanguageToTest {
+     std::string accept_language;
+@@ -700,6 +726,13 @@ class LanguageSettingsPrivateApiTestDelayInit
+   LanguageSettingsPrivateApiTestDelayInit() = default;
+ 
+  protected:
++  void InitFeatures() override {
++    // Force Windows hybrid spellcheck and delayed initialization of the
++    // spellcheck service to be enabled.
++    feature_list_.InitAndEnableFeature(
++        spellcheck::kWinDelaySpellcheckServiceInit);
++  }
++
+   void AddSpellcheckLanguagesForTesting(
+       const std::vector<std::string>& spellcheck_languages_for_testing)
+       override {
+diff --git a/chrome/browser/renderer_context_menu/spelling_menu_observer_browsertest.cc b/chrome/browser/renderer_context_menu/spelling_menu_observer_browsertest.cc
+index bd0d77323277ee422ec4f75cee9f7d4e9bf198b3..d0ed451fe104b9671d6002ca72e8ca3a620cb111 100644
+--- a/chrome/browser/renderer_context_menu/spelling_menu_observer_browsertest.cc
++++ b/chrome/browser/renderer_context_menu/spelling_menu_observer_browsertest.cc
+@@ -30,7 +30,7 @@ namespace {
+ // accesses resources.
+ class SpellingMenuObserverTest : public InProcessBrowserTest {
+  public:
+-  SpellingMenuObserverTest() = default;
++  SpellingMenuObserverTest();
+ 
+   void SetUpOnMainThread() override {
+     Reset(false);
+@@ -54,12 +54,6 @@ class SpellingMenuObserverTest : public InProcessBrowserTest {
+       content::BrowserContext* context) {
+     auto spellcheck_service = std::make_unique<SpellcheckService>(context);
+ 
+-    // With delayed initialization, we need to initialize dictionaries.
+-    spellcheck_service->InitializeDictionaries(
+-        base::BindOnce(&SpellingMenuObserverTest::OnSuggestionsComplete,
+-                       base::Unretained(this)));
+-    RunUntilCallbackReceived();
+-
+     // Call SetLanguage to assure that the platform spellchecker is initialized.
+     spellcheck_platform::SetLanguage(
+         spellcheck_service->platform_spell_checker(), "en-US",
+@@ -173,6 +167,16 @@ class SpellingMenuObserverTest : public InProcessBrowserTest {
+ #endif  // BUILDFLAG(IS_WIN) && BUILDFLAG(USE_BROWSER_SPELLCHECKER)
+ };
+ 
++#if BUILDFLAG(IS_WIN) && BUILDFLAG(USE_BROWSER_SPELLCHECKER)
++SpellingMenuObserverTest::SpellingMenuObserverTest() {
++  feature_list_.InitWithFeatures(
++      /*enabled_features=*/{},
++      /*disabled_features=*/{spellcheck::kWinDelaySpellcheckServiceInit});
++}
++#else
++SpellingMenuObserverTest::SpellingMenuObserverTest() = default;
++#endif  // BUILDFLAG(IS_WIN) && BUILDFLAG(USE_BROWSER_SPELLCHECKER)
++
+ SpellingMenuObserverTest::~SpellingMenuObserverTest() = default;
+ 
+ }  // namespace
+diff --git a/chrome/browser/site_isolation/spellcheck_per_process_browsertest.cc b/chrome/browser/site_isolation/spellcheck_per_process_browsertest.cc
+index 8aef94fbd6788d1216648d873cdea3136d8e51c0..1a18086f01c21b34e1ce5ecf750591456a8f3d32 100644
+--- a/chrome/browser/site_isolation/spellcheck_per_process_browsertest.cc
++++ b/chrome/browser/site_isolation/spellcheck_per_process_browsertest.cc
+@@ -133,21 +133,26 @@ class MockSpellCheckHost : spellcheck::mojom::SpellCheckHost {
+ #if BUILDFLAG(IS_WIN)
+   void InitializeDictionaries(
+       InitializeDictionariesCallback callback) override {
+-    SpellcheckService* spellcheck = SpellcheckServiceFactory::GetForContext(
+-        process_host()->GetBrowserContext());
+-
+-    if (!spellcheck) {  // Teardown.
+-      std::move(callback).Run(/*dictionaries=*/{}, /*custom_words=*/{},
+-                              /*enable=*/false);
++    if (base::FeatureList::IsEnabled(
++            spellcheck::kWinDelaySpellcheckServiceInit)) {
++      SpellcheckService* spellcheck = SpellcheckServiceFactory::GetForContext(
++          process_host()->GetBrowserContext());
++
++      if (!spellcheck) {  // Teardown.
++        std::move(callback).Run(/*dictionaries=*/{}, /*custom_words=*/{},
++                                /*enable=*/false);
++        return;
++      }
++
++      dictionaries_loaded_callback_ = std::move(callback);
++
++      spellcheck->InitializeDictionaries(
++          base::BindOnce(&MockSpellCheckHost::OnDictionariesInitialized,
++                         base::Unretained(this)));
+       return;
+     }
+ 
+-    dictionaries_loaded_callback_ = std::move(callback);
+-
+-    spellcheck->InitializeDictionaries(
+-        base::BindOnce(&MockSpellCheckHost::OnDictionariesInitialized,
+-                       base::Unretained(this)));
+-    return;
++    NOTREACHED();
+   }
+ 
+   void OnDictionariesInitialized() {
+@@ -259,7 +264,17 @@ class ChromeSitePerProcessSpellCheckTest : public ChromeSitePerProcessTest {
+  public:
+   ChromeSitePerProcessSpellCheckTest() = default;
+ 
+-  void SetUp() override { ChromeSitePerProcessTest::SetUp(); }
++  void SetUp() override {
++#if BUILDFLAG(IS_WIN) && BUILDFLAG(USE_BROWSER_SPELLCHECKER)
++    // When delayed initialization of the spellcheck service is enabled by
++    // default, want to maintain test coverage for the older code path that
++    // initializes spellcheck on browser startup.
++    feature_list_.InitAndDisableFeature(
++        spellcheck::kWinDelaySpellcheckServiceInit);
++#endif  // BUILDFLAG(IS_WIN) && BUILDFLAG(USE_BROWSER_SPELLCHECKER)
++
++    ChromeSitePerProcessTest::SetUp();
++  }
+ 
+  protected:
+   // Tests that spelling in out-of-process subframes is checked.
+@@ -366,3 +381,29 @@ IN_PROC_BROWSER_TEST_F(ChromeSitePerProcessSpellCheckTest,
+   EXPECT_TRUE(host->SpellingPanelVisible());
+ }
+ #endif  // BUILDFLAG(HAS_SPELLCHECK_PANEL)
++
++#if BUILDFLAG(IS_WIN) && BUILDFLAG(USE_BROWSER_SPELLCHECKER)
++class ChromeSitePerProcessSpellCheckTestDelayInit
++    : public ChromeSitePerProcessSpellCheckTest {
++ public:
++  ChromeSitePerProcessSpellCheckTestDelayInit() = default;
++
++  void SetUp() override {
++    // Don't initialize the SpellcheckService on browser launch.
++    feature_list_.InitAndEnableFeature(
++        spellcheck::kWinDelaySpellcheckServiceInit);
++
++    ChromeSitePerProcessTest::SetUp();
++  }
++};
++
++IN_PROC_BROWSER_TEST_F(ChromeSitePerProcessSpellCheckTestDelayInit,
++                       OOPIFSpellCheckTest) {
++  RunOOPIFSpellCheckTest();
++}
++
++IN_PROC_BROWSER_TEST_F(ChromeSitePerProcessSpellCheckTestDelayInit,
++                       OOPIFDisabledSpellCheckTest) {
++  RunOOPIFDisabledSpellCheckTest();
++}
++#endif  // BUILDFLAG(IS_WIN) && BUILDFLAG(USE_BROWSER_SPELLCHECKER)
+diff --git a/chrome/browser/spellchecker/spell_check_host_chrome_impl.cc b/chrome/browser/spellchecker/spell_check_host_chrome_impl.cc
+index c51c5747f45010548fe0cb7d31016605cf43c8e3..a99eb10c4ba77a1d3a89a308acffb5064d690b4a 100644
+--- a/chrome/browser/spellchecker/spell_check_host_chrome_impl.cc
++++ b/chrome/browser/spellchecker/spell_check_host_chrome_impl.cc
+@@ -186,21 +186,27 @@ void SpellCheckHostChromeImpl::InitializeDictionaries(
+     InitializeDictionariesCallback callback) {
+   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+ 
+-  // Initialize the spellcheck service if needed. Initialization must
+-  // happen on UI thread.
+-  SpellcheckService* spellcheck = GetSpellcheckService();
++  if (base::FeatureList::IsEnabled(
++          spellcheck::kWinDelaySpellcheckServiceInit)) {
++    // Initialize the spellcheck service if needed. Initialization must
++    // happen on UI thread.
++    SpellcheckService* spellcheck = GetSpellcheckService();
++
++    if (!spellcheck) {  // Teardown.
++      std::move(callback).Run(/*dictionaries=*/{}, /*custom_words=*/{},
++                              /*enable=*/false);
++      return;
++    }
+ 
+-  if (!spellcheck) {  // Teardown.
+-    std::move(callback).Run(/*dictionaries=*/{}, /*custom_words=*/{},
+-                            /*enable=*/false);
++    dictionaries_loaded_callback_ = std::move(callback);
++
++    spellcheck->InitializeDictionaries(
++        base::BindOnce(&SpellCheckHostChromeImpl::OnDictionariesInitialized,
++                       weak_factory_.GetWeakPtr()));
+     return;
+   }
+ 
+-  dictionaries_loaded_callback_ = std::move(callback);
+-
+-  spellcheck->InitializeDictionaries(
+-      base::BindOnce(&SpellCheckHostChromeImpl::OnDictionariesInitialized,
+-                     weak_factory_.GetWeakPtr()));
++  NOTREACHED();
+ }
+ 
+ void SpellCheckHostChromeImpl::OnDictionariesInitialized() {
+diff --git a/chrome/browser/spellchecker/spell_check_host_chrome_impl_win_browsertest.cc b/chrome/browser/spellchecker/spell_check_host_chrome_impl_win_browsertest.cc
+index 31ab441aedd69c08c6f1beefa2129e60bd44a7f3..308c90516a9881b82da5cedec5d80208dbccdced 100644
+--- a/chrome/browser/spellchecker/spell_check_host_chrome_impl_win_browsertest.cc
++++ b/chrome/browser/spellchecker/spell_check_host_chrome_impl_win_browsertest.cc
+@@ -32,7 +32,12 @@ class SpellCheckHostChromeImplWinBrowserTest : public InProcessBrowserTest {
+  public:
+   SpellCheckHostChromeImplWinBrowserTest() = default;
+ 
+-  void SetUp() override { InProcessBrowserTest::SetUp(); }
++  void SetUp() override {
++    // Don't delay initialization of the SpellcheckService on browser launch.
++    feature_list_.InitAndDisableFeature(
++        spellcheck::kWinDelaySpellcheckServiceInit);
++    InProcessBrowserTest::SetUp();
++  }
+ 
+   void SetUpOnMainThread() override {
+     content::BrowserContext* context = browser()->profile();
+@@ -50,22 +55,7 @@ class SpellCheckHostChromeImplWinBrowserTest : public InProcessBrowserTest {
+ 
+   void TearDownOnMainThread() override { renderer_.reset(); }
+ 
+-  void InitializeSpellcheckService() {
+-    spell_check_host_->InitializeDictionaries(base::BindOnce(
+-        &SpellCheckHostChromeImplWinBrowserTest::InitializeDictionariesCallback,
+-        base::Unretained(this)));
+-    RunUntilResultReceived();
+-  }
+-
+-  void InitializeDictionariesCallback(
+-      std::vector<spellcheck::mojom::SpellCheckBDictLanguagePtr> dictionaries,
+-      const std::vector<std::string>& custom_words,
+-      bool enable) {
+-    received_result_ = true;
+-    if (quit_) {
+-      std::move(quit_).Run();
+-    }
+-  }
++  virtual void InitializeSpellcheckService() {}
+ 
+   void OnSpellcheckResult(const std::vector<SpellCheckResult>& result) {
+     received_result_ = true;
+@@ -139,3 +129,41 @@ void SpellCheckHostChromeImplWinBrowserTest::RunSpellCheckReturnMessageTest() {
+   EXPECT_EQ(result_[0].length, 2);
+   EXPECT_EQ(result_[0].decoration, SpellCheckResult::SPELLING);
+ }
++
++class SpellCheckHostChromeImplWinBrowserTestDelayInit
++    : public SpellCheckHostChromeImplWinBrowserTest {
++ public:
++  SpellCheckHostChromeImplWinBrowserTestDelayInit() = default;
++
++  void SetUp() override {
++    // Don't initialize the SpellcheckService on browser launch.
++    feature_list_.InitAndEnableFeature(
++        spellcheck::kWinDelaySpellcheckServiceInit);
++    InProcessBrowserTest::SetUp();
++  }
++
++  void InitializeSpellcheckService() override {
++    // With the kWinDelaySpellcheckServiceInit feature flag set, the spellcheck
++    // service is not initialized when instantiated. Call InitializeDictionaries
++    // to load the dictionaries.
++    spell_check_host_->InitializeDictionaries(
++        base::BindOnce(&SpellCheckHostChromeImplWinBrowserTestDelayInit::
++                           InitializeDictionariesCallback,
++                       base::Unretained(this)));
++    RunUntilResultReceived();
++  }
++
++  void InitializeDictionariesCallback(
++      std::vector<spellcheck::mojom::SpellCheckBDictLanguagePtr> dictionaries,
++      const std::vector<std::string>& custom_words,
++      bool enable) {
++    received_result_ = true;
++    if (quit_)
++      std::move(quit_).Run();
++  }
++};
++
++IN_PROC_BROWSER_TEST_F(SpellCheckHostChromeImplWinBrowserTestDelayInit,
++                       SpellCheckReturnMessage) {
++  RunSpellCheckReturnMessageTest();
++}
+diff --git a/chrome/browser/spellchecker/spellcheck_service.cc b/chrome/browser/spellchecker/spellcheck_service.cc
+index 02da80b42f936f347c9043f4499d9a324bdf43d2..8fbb2025d157e58c90c701f9e3478f6c99b88aa1 100644
+--- a/chrome/browser/spellchecker/spellcheck_service.cc
++++ b/chrome/browser/spellchecker/spellcheck_service.cc
+@@ -170,7 +170,9 @@ SpellcheckService::SpellcheckService(content::BrowserContext* context)
+   custom_dictionary_->Load();
+ 
+ #if BUILDFLAG(IS_WIN)
+-  if (spellcheck::UseBrowserSpellChecker()) {
++  if (spellcheck::UseBrowserSpellChecker() &&
++      base::FeatureList::IsEnabled(
++          spellcheck::kWinDelaySpellcheckServiceInit)) {
+     // If initialization of the spellcheck service is on-demand, it is up to the
+     // instantiator of the spellcheck service to call InitializeDictionaries
+     // with a callback.
+@@ -492,7 +494,9 @@ void SpellcheckService::LoadDictionaries() {
+   }
+ 
+ #if BUILDFLAG(USE_BROWSER_SPELLCHECKER)
+-  if (spellcheck::UseBrowserSpellChecker()) {
++  if (base::FeatureList::IsEnabled(
++          spellcheck::kWinDelaySpellcheckServiceInit) &&
++      spellcheck::UseBrowserSpellChecker()) {
+     // Only want to fire the callback on first call to LoadDictionaries
+     // originating from InitializeDictionaries, since supported platform
+     // dictionaries are cached throughout the browser session and not
+@@ -520,7 +524,9 @@ bool SpellcheckService::IsSpellcheckEnabled() const {
+ 
+   bool enable_if_uninitialized = false;
+ #if BUILDFLAG(IS_WIN)
+-  if (spellcheck::UseBrowserSpellChecker()) {
++  if (spellcheck::UseBrowserSpellChecker() &&
++      base::FeatureList::IsEnabled(
++          spellcheck::kWinDelaySpellcheckServiceInit)) {
+     // If initialization of the spellcheck service is on-demand, the
+     // renderer-side SpellCheck object needs to start out as enabled in order
+     // for a click on editable content to initialize the spellcheck service.
+diff --git a/chrome/browser/spellchecker/spellcheck_service_browsertest.cc b/chrome/browser/spellchecker/spellcheck_service_browsertest.cc
+index d99667b86795215717dbb25dfefdf0a32f7cd089..5a6dd4dcc4467601a3197f5b273231b2c95d8cdf 100644
+--- a/chrome/browser/spellchecker/spellcheck_service_browsertest.cc
++++ b/chrome/browser/spellchecker/spellcheck_service_browsertest.cc
+@@ -712,6 +712,32 @@ class SpellcheckServiceWindowsHybridBrowserTest
+       : SpellcheckServiceBrowserTest(/* use_browser_spell_checker=*/true) {}
+ };
+ 
++IN_PROC_BROWSER_TEST_F(SpellcheckServiceWindowsHybridBrowserTest,
++                       WindowsHybridSpellcheck) {
++  // This test specifically covers the case where spellcheck delayed
++  // initialization is not enabled, so return early if it is. Other tests
++  // cover the case where delayed initialization is enabled.
++  if (base::FeatureList::IsEnabled(spellcheck::kWinDelaySpellcheckServiceInit))
++    return;
++
++  ASSERT_TRUE(spellcheck::UseBrowserSpellChecker());
++
++  // Note that the base class forces dictionary sync to not be performed, which
++  // on its own would have created a SpellcheckService object. So testing here
++  // that we are still instantiating the SpellcheckService as a browser startup
++  // task to support hybrid spellchecking.
++  SpellcheckService* service = static_cast<SpellcheckService*>(
++      SpellcheckServiceFactory::GetInstance()->GetServiceForBrowserContext(
++          GetContext(), /* create */ false));
++  ASSERT_NE(nullptr, service);
++
++  // The list of Windows spellcheck languages should have been populated by at
++  // least one language. This assures that the spellcheck context menu will
++  // include Windows spellcheck languages that lack Hunspell support.
++  EXPECT_TRUE(service->dictionaries_loaded());
++  EXPECT_FALSE(service->windows_spellcheck_dictionary_map_.empty());
++}
++
+ class SpellcheckServiceWindowsHybridBrowserTestDelayInit
+     : public SpellcheckServiceBrowserTest {
+  public:
+@@ -719,6 +745,10 @@ class SpellcheckServiceWindowsHybridBrowserTestDelayInit
+       : SpellcheckServiceBrowserTest(/* use_browser_spell_checker=*/true) {}
+ 
+   void SetUp() override {
++    // Don't initialize the SpellcheckService on browser launch.
++    feature_list_.InitAndEnableFeature(
++        spellcheck::kWinDelaySpellcheckServiceInit);
++
+     // Add command line switch that forces first run state, to test whether
+     // primary preferred language has its spellcheck dictionary enabled by
+     // default for non-Hunspell languages.
+@@ -808,9 +838,10 @@ IN_PROC_BROWSER_TEST_F(SpellcheckServiceWindowsHybridBrowserTestDelayInit,
+                        WindowsHybridSpellcheckDelayInit) {
+   ASSERT_TRUE(spellcheck::UseBrowserSpellChecker());
+ 
+-  // The base class forces dictionary sync to be skipped, so the
+-  // SpellcheckService object should not have been created on browser startup
+-  // because. Verify this is the case.
++  // Note that the base class forces dictionary sync to not be performed, and
++  // the kWinDelaySpellcheckServiceInit flag is set, which together should
++  // prevent creation of a SpellcheckService object on browser startup. So
++  // testing here that this is indeed the case.
+   SpellcheckService* service = static_cast<SpellcheckService*>(
+       SpellcheckServiceFactory::GetInstance()->GetServiceForBrowserContext(
+           GetContext(), /* create */ false));
+diff --git a/chrome/browser/spellchecker/spellcheck_service_unittest.cc b/chrome/browser/spellchecker/spellcheck_service_unittest.cc
+index be073ddd362c6a8e9b93961eba2c5a7d4a978b5e..68c479ca1e8fd93ef661258823122cbc6277ad95 100644
+--- a/chrome/browser/spellchecker/spellcheck_service_unittest.cc
++++ b/chrome/browser/spellchecker/spellcheck_service_unittest.cc
+@@ -181,11 +181,15 @@ class SpellcheckServiceHybridUnitTestBase
+ 
+  protected:
+   void SetUp() override {
++    InitFeatures();
++
+     // Use SetTestingFactoryAndUse to force creation and initialization.
+     SpellcheckServiceFactory::GetInstance()->SetTestingFactoryAndUse(
+         &profile_, base::BindRepeating(&BuildSpellcheckService));
+   }
+ 
++  virtual void InitFeatures() {}
++
+   virtual void InitializeSpellcheckService(
+       const std::vector<std::string>& spellcheck_languages_for_testing) {
+     // Fake the presence of Windows spellcheck dictionaries.
+@@ -215,6 +219,8 @@ class SpellcheckServiceHybridUnitTestBase
+   static const std::vector<std::string>
+       windows_spellcheck_languages_for_testing_;
+ 
++  base::test::ScopedFeatureList feature_list_;
++
+   raw_ptr<SpellcheckService> spellcheck_service_;
+ };
+ 
+@@ -327,6 +333,18 @@ const std::vector<std::string> SpellcheckServiceHybridUnitTestBase::
+                              // dictionaries.
+ };
+ 
++class GetDictionariesHybridUnitTestNoDelayInit
++    : public SpellcheckServiceHybridUnitTestBase,
++      public testing::WithParamInterface<TestCase> {
++ protected:
++  void InitFeatures() override {
++    // Disable kWinDelaySpellcheckServiceInit, as the case where it's enabled
++    // is tested in SpellcheckServiceWindowsDictionaryMappingUnitTestDelayInit.
++    feature_list_.InitAndDisableFeature(
++        spellcheck::kWinDelaySpellcheckServiceInit);
++  }
++};
++
+ static const TestCase kHybridGetDictionariesParams[] = {
+     // Galician (gl) has only Windows support, no Hunspell dictionary. Croatian
+     // (hr) has only Hunspell support, no local Windows dictionary. First
+@@ -379,6 +397,16 @@ static const TestCase kHybridGetDictionariesParams[] = {
+     TestCase("it,it-IT", {"it", "it-IT"}, {"it", "it-IT"}, {"it", "it-IT"}),
+ };
+ 
++INSTANTIATE_TEST_SUITE_P(TestCases,
++                         GetDictionariesHybridUnitTestNoDelayInit,
++                         testing::ValuesIn(kHybridGetDictionariesParams));
++
++TEST_P(GetDictionariesHybridUnitTestNoDelayInit, GetDictionaries) {
++  RunGetDictionariesTest(GetParam().accept_languages,
++                         GetParam().spellcheck_dictionaries,
++                         GetParam().expected_dictionaries);
++}
++
+ struct DictionaryMappingTestCase {
+   std::string full_tag;
+   std::string expected_accept_language;
+@@ -401,6 +429,18 @@ std::ostream& operator<<(std::ostream& out,
+   return out;
+ }
+ 
++class SpellcheckServiceWindowsDictionaryMappingUnitTest
++    : public SpellcheckServiceHybridUnitTestBase,
++      public testing::WithParamInterface<DictionaryMappingTestCase> {
++ protected:
++  void InitFeatures() override {
++    // Disable kWinDelaySpellcheckServiceInit, as the case where it's enabled
++    // is tested in SpellcheckServiceWindowsDictionaryMappingUnitTestDelayInit.
++    feature_list_.InitAndDisableFeature(
++        spellcheck::kWinDelaySpellcheckServiceInit);
++  }
++};
++
+ static const DictionaryMappingTestCase kHybridDictionaryMappingsParams[] = {
+     DictionaryMappingTestCase({"en-CA", "en-CA", "en-CA", "en", "en"}),
+     DictionaryMappingTestCase({"en-PH", "en", "en", "", ""}),
+@@ -423,6 +463,18 @@ static const DictionaryMappingTestCase kHybridDictionaryMappingsParams[] = {
+     DictionaryMappingTestCase({"pt-BR", "pt-BR", "pt-BR", "pt", "pt"}),
+ };
+ 
++INSTANTIATE_TEST_SUITE_P(TestCases,
++                         SpellcheckServiceWindowsDictionaryMappingUnitTest,
++                         testing::ValuesIn(kHybridDictionaryMappingsParams));
++
++TEST_P(SpellcheckServiceWindowsDictionaryMappingUnitTest, CheckMappings) {
++  RunDictionaryMappingTest(
++      GetParam().full_tag, GetParam().expected_accept_language,
++      GetParam().expected_tag_passed_to_spellcheck,
++      GetParam().expected_accept_language_generic,
++      GetParam().expected_tag_passed_to_spellcheck_generic);
++}
++
+ class SpellcheckServiceHybridUnitTestDelayInitBase
+     : public SpellcheckServiceHybridUnitTestBase {
+  public:
+@@ -435,6 +487,12 @@ class SpellcheckServiceHybridUnitTestDelayInitBase
+   }
+ 
+  protected:
++  void InitFeatures() override {
++    // Don't initialize the SpellcheckService on browser launch.
++    feature_list_.InitAndEnableFeature(
++        spellcheck::kWinDelaySpellcheckServiceInit);
++  }
++
+   void InitializeSpellcheckService(
+       const std::vector<std::string>& spellcheck_languages_for_testing)
+       override {
+diff --git a/components/spellcheck/common/spellcheck_features.cc b/components/spellcheck/common/spellcheck_features.cc
+index ab07d966779449efcb0bad95ebe05e6018300048..527fa5d72369bb1194684527312eb093946d41c0 100644
+--- a/components/spellcheck/common/spellcheck_features.cc
++++ b/components/spellcheck/common/spellcheck_features.cc
+@@ -41,6 +41,8 @@ ScopedDisableBrowserSpellCheckerForTesting::
+   g_browser_spell_checker_enabled = previous_value_;
+ }
+ 
++BASE_FEATURE(kWinDelaySpellcheckServiceInit, base::FEATURE_ENABLED_BY_DEFAULT);
++
+ #endif  // BUILDFLAG(IS_WIN)
+ 
+ #if BUILDFLAG(IS_ANDROID)
+diff --git a/components/spellcheck/common/spellcheck_features.h b/components/spellcheck/common/spellcheck_features.h
+index 01e193221c74f0e0bd8620627455f92741448075..7929156c59d078b3d4299bb44ea28bc61bbe0086 100644
+--- a/components/spellcheck/common/spellcheck_features.h
++++ b/components/spellcheck/common/spellcheck_features.h
+@@ -30,6 +30,25 @@ class ScopedDisableBrowserSpellCheckerForTesting {
+   const bool previous_value_;
+ };
+ 
++// If the kWinDelaySpellcheckServiceInit feature flag is enabled, don't
++// initialize the spellcheck dictionaries when the SpellcheckService is
++// instantiated. With this flag set: (1) Completing the initialization of the
++// spellcheck service is on-demand, invoked by calling
++// SpellcheckService::InitializeDictionaries with a callback to indicate when
++// the operation completes. (2) The call to create the spellcheck service in
++// ChromeBrowserMainParts::PreMainMessageLoopRunImpl will be skipped. Chromium
++// will still by default instantiate the spellcheck service on startup for
++// custom dictionary synchronization, but will not load Windows spellcheck
++// dictionaries. The command line for launching the browser with Windows hybrid
++// spellchecking enabled but no initialization of the spellcheck service is:
++//    chrome
++//    --enable-features=WinDelaySpellcheckServiceInit
++// and if instantiation of the spellcheck service needs to be completely
++// disabled:
++//     chrome
++//    --enable-features=WinDelaySpellcheckServiceInit
++//    --disable-sync-types="Dictionary"
++BASE_DECLARE_FEATURE(kWinDelaySpellcheckServiceInit);
+ #endif  // BUILDFLAG(IS_WIN)
+ 
+ #if BUILDFLAG(IS_ANDROID)
+diff --git a/components/spellcheck/renderer/spellcheck_provider.cc b/components/spellcheck/renderer/spellcheck_provider.cc
+index 20e73dd66865f1d7573adc092d8747e3b3252cfd..0bec57f9a7276c3623edd4fcf009d7b35e453df4 100644
+--- a/components/spellcheck/renderer/spellcheck_provider.cc
++++ b/components/spellcheck/renderer/spellcheck_provider.cc
+@@ -126,7 +126,9 @@ void SpellCheckProvider::RequestTextChecking(
+ #if BUILDFLAG(USE_BROWSER_SPELLCHECKER)
+   if (spellcheck::UseBrowserSpellChecker()) {
+ #if BUILDFLAG(IS_WIN)
+-    if (!dictionaries_loaded_) {
++    if (base::FeatureList::IsEnabled(
++            spellcheck::kWinDelaySpellcheckServiceInit) &&
++        !dictionaries_loaded_) {
+       // Initialize the spellcheck service on demand (this spellcheck request
+       // could be the result of the first click in editable content), then
+       // complete the text check request when the dictionaries are loaded.
+diff --git a/components/spellcheck/renderer/spellcheck_provider_test.cc b/components/spellcheck/renderer/spellcheck_provider_test.cc
+index 04dcb599f5dd93d3e381c243e5ba81fbec8a3790..12c32fd631ff93f1d1ff3c7d2a19924e8909c099 100644
+--- a/components/spellcheck/renderer/spellcheck_provider_test.cc
++++ b/components/spellcheck/renderer/spellcheck_provider_test.cc
+@@ -188,8 +188,14 @@ void TestingSpellCheckProvider::FillSuggestionList(const std::u16string&,
+ #if BUILDFLAG(IS_WIN)
+ void TestingSpellCheckProvider::InitializeDictionaries(
+     InitializeDictionariesCallback callback) {
+-  std::move(callback).Run(/*dictionaries=*/{}, /*custom_words=*/{},
+-                          /*enable=*/false);
++  if (base::FeatureList::IsEnabled(
++          spellcheck::kWinDelaySpellcheckServiceInit)) {
++    std::move(callback).Run(/*dictionaries=*/{}, /*custom_words=*/{},
++                            /*enable=*/false);
++    return;
++  }
++
++  NOTREACHED();
+ }
+ #endif  // BUILDFLAG(IS_WIN)
+ #endif  // BUILDFLAG(USE_BROWSER_SPELLCHECKER)
+diff --git a/components/spellcheck/renderer/spellcheck_provider_unittest.cc b/components/spellcheck/renderer/spellcheck_provider_unittest.cc
+index 487cdb1f871868a7fed8ae2ba1adc816c581d0e2..6e1da0564754063e78ad69997be71bbc95e27b39 100644
+--- a/components/spellcheck/renderer/spellcheck_provider_unittest.cc
++++ b/components/spellcheck/renderer/spellcheck_provider_unittest.cc
+@@ -65,12 +65,34 @@ class HybridSpellCheckTest
+   HybridSpellCheckTest() : provider_(&embedder_provider_) {}
+   ~HybridSpellCheckTest() override = default;
+ 
++  void SetUp() override {
++    // Don't delay initialization of the SpellcheckService on browser launch.
++    feature_list_.InitAndDisableFeature(
++        spellcheck::kWinDelaySpellcheckServiceInit);
++  }
++
++  void RunShouldUseBrowserSpellCheckOnlyWhenNeededTest();
++
+  protected:
++  base::test::ScopedFeatureList feature_list_;
+   base::test::SingleThreadTaskEnvironment task_environment_;
+   spellcheck::EmptyLocalInterfaceProvider embedder_provider_;
+   TestingSpellCheckProvider provider_;
+ };
+ 
++// Test fixture for testing hybrid check cases with delayed initialization of
++// the spellcheck service.
++class HybridSpellCheckTestDelayInit : public HybridSpellCheckTest {
++ public:
++  HybridSpellCheckTestDelayInit() = default;
++
++  void SetUp() override {
++    // Don't initialize the SpellcheckService on browser launch.
++    feature_list_.InitAndEnableFeature(
++        spellcheck::kWinDelaySpellcheckServiceInit);
++  }
++};
++
+ // Test fixture for testing combining results from both the native spell checker
+ // and Hunspell.
+ class CombineSpellCheckResultsTest
+@@ -173,6 +195,10 @@ INSTANTIATE_TEST_SUITE_P(
+     testing::ValuesIn(kSpellCheckProviderHybridTestsParams));
+ 
+ TEST_P(HybridSpellCheckTest, ShouldUseBrowserSpellCheckOnlyWhenNeeded) {
++  RunShouldUseBrowserSpellCheckOnlyWhenNeededTest();
++}
++
++void HybridSpellCheckTest::RunShouldUseBrowserSpellCheckOnlyWhenNeededTest() {
+   const auto& test_case = GetParam();
+ 
+   FakeTextCheckingResult completion;
+@@ -191,6 +217,20 @@ TEST_P(HybridSpellCheckTest, ShouldUseBrowserSpellCheckOnlyWhenNeeded) {
+   EXPECT_EQ(completion.cancellation_count_, 0U);
+ }
+ 
++// Tests that the SpellCheckProvider calls into the native spell checker only
++// when needed when the code path through
++// SpellCheckProvider::RequestTextChecking is that used when the spellcheck
++// service is initialized on demand.
++INSTANTIATE_TEST_SUITE_P(
++    SpellCheckProviderHybridTests,
++    HybridSpellCheckTestDelayInit,
++    testing::ValuesIn(kSpellCheckProviderHybridTestsParams));
++
++TEST_P(HybridSpellCheckTestDelayInit,
++       ShouldUseBrowserSpellCheckOnlyWhenNeeded) {
++  RunShouldUseBrowserSpellCheckOnlyWhenNeededTest();
++}
++
+ // Tests that the SpellCheckProvider can correctly combine results from the
+ // native spell checker and Hunspell.
+ INSTANTIATE_TEST_SUITE_P(

patches/chromium/revert_code_health_clean_up_stale_macwebcontentsocclusion.patch

@@ -254,10 +254,10 @@ index 17d6d7d935f93afefa9123f56ef9c138c3070f93..8dfa7501a6a2998e107bf9b51f5e5c3d
  }
  
 diff --git a/content/common/features.cc b/content/common/features.cc
-index 942f204b4c09787870c14e068dba543e7b64d442..6ccd0081e3c3ef88794ab82fc1282a1d91e047ea 100644
+index 4419e36c81aca962e85892cc2e0af3dee31a86c3..5b1bfeba20bd5dde48145ab2f94632735d63d316 100644
 --- a/content/common/features.cc
 +++ b/content/common/features.cc
-@@ -305,6 +305,14 @@ BASE_FEATURE(kInterestGroupUpdateIfOlderThan, base::FEATURE_ENABLED_BY_DEFAULT);
+@@ -306,6 +306,14 @@ BASE_FEATURE(kInterestGroupUpdateIfOlderThan, base::FEATURE_ENABLED_BY_DEFAULT);
  BASE_FEATURE(kIOSurfaceCapturer, base::FEATURE_ENABLED_BY_DEFAULT);
  #endif
  
@@ -273,10 +273,10 @@ index 942f204b4c09787870c14e068dba543e7b64d442..6ccd0081e3c3ef88794ab82fc1282a1d
  BASE_FEATURE(kKeepChildProcessAfterIPCReset, base::FEATURE_DISABLED_BY_DEFAULT);
  
 diff --git a/content/common/features.h b/content/common/features.h
-index 243c4b57083c58c889e9e9d8034dc109420e2fc2..13b7a0c529e7214369c4affebe8fb95e2ddc256e 100644
+index faef439b47b162b75a26a5979ae31dc0532bb214..39e283445c643e11847b0ffdc8c06f79028988c7 100644
 --- a/content/common/features.h
 +++ b/content/common/features.h
-@@ -107,6 +107,9 @@ CONTENT_EXPORT BASE_DECLARE_FEATURE(kInterestGroupUpdateIfOlderThan);
+@@ -110,6 +110,9 @@ CONTENT_EXPORT BASE_DECLARE_FEATURE(kInterestGroupUpdateIfOlderThan);
  #if BUILDFLAG(IS_MAC)
  CONTENT_EXPORT BASE_DECLARE_FEATURE(kIOSurfaceCapturer);
  #endif

patches/chromium/revert_partial_remove_unused_prehandlemouseevent.patch

@@ -54,10 +54,10 @@ index 5b0f0b28c3f36315d5bb12ad7e35f21c91a1e8b6..08ca1a3fc2add9cf93b078b9136d9aa6
      if (mouse_event_callback.Run(mouse_event)) {
        return;
 diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
-index a9813ead175b478227bb91daf0d23cffc1bedca6..4777db11f1fbde96c7b117dfe0241bb5c34db126 100644
+index 6edd4d673dd61b396aaf121ff3e6810fd0b4ba00..3c25f0d1111eaebf4fb62c9241d237dea3c2a416 100644
 --- a/content/browser/web_contents/web_contents_impl.cc
 +++ b/content/browser/web_contents/web_contents_impl.cc
-@@ -4466,6 +4466,12 @@ void WebContentsImpl::RenderWidgetWasResized(
+@@ -4478,6 +4478,12 @@ void WebContentsImpl::RenderWidgetWasResized(
                               width_changed);
  }
  
@@ -71,10 +71,10 @@ index a9813ead175b478227bb91daf0d23cffc1bedca6..4777db11f1fbde96c7b117dfe0241bb5
                                            const gfx::PointF& client_pt) {
    if (delegate_) {
 diff --git a/content/browser/web_contents/web_contents_impl.h b/content/browser/web_contents/web_contents_impl.h
-index 247e71fa9a43116b40cfffd8da0169223272d9c9..48ac6629a904a135f3e3ca7e1f924807e575675a 100644
+index 9b065992fc577084ef16aaef1436fd0855e32981..0f230a7ecaa04e8050899525d606541432dada1e 100644
 --- a/content/browser/web_contents/web_contents_impl.h
 +++ b/content/browser/web_contents/web_contents_impl.h
-@@ -1107,6 +1107,7 @@ class CONTENT_EXPORT WebContentsImpl
+@@ -1114,6 +1114,7 @@ class CONTENT_EXPORT WebContentsImpl
  
    double GetPendingZoomLevel(RenderWidgetHostImpl* rwh) override;
  

patches/chromium/revert_views_remove_desktopwindowtreehostwin_window_enlargement.patch

@@ -10,10 +10,10 @@ on Windows.  We should refactor our code so that this patch isn't
 necessary.
 
 diff --git a/testing/variations/fieldtrial_testing_config.json b/testing/variations/fieldtrial_testing_config.json
-index 7884bdff1cce1a7a52221f1d7bf5933cd4518b83..be66b04538b2969ba3f8ada0f63660eea586c42b 100644
+index 6d478df9ae82edc4bf6994e775a4d716770fdad1..5b7c4a7e4baef8a2dab1a41ff9962f2bbbbd95a9 100644
 --- a/testing/variations/fieldtrial_testing_config.json
 +++ b/testing/variations/fieldtrial_testing_config.json
-@@ -25301,6 +25301,21 @@
+@@ -25347,6 +25347,21 @@
              ]
          }
      ],
@@ -67,7 +67,7 @@ index c1d8107ec3e32d31811572aa1d7a7c7a242da7d9..463abf871c7e169dc1ca9f523d74fc14
  
  }  // namespace views::features
 diff --git a/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc b/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc
-index d58b59288d881a2d74ea357f1e9e27870d24ac72..956dc87cb07559038a63cec0b5174cec09619bdb 100644
+index 89287b68398e9121959e7750644d37072e8e489b..29bf4dfbe2cf0af5a1369c4d3e17e50a198c78c6 100644
 --- a/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc
 +++ b/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc
 @@ -84,6 +84,23 @@ namespace {
@@ -94,7 +94,7 @@ index d58b59288d881a2d74ea357f1e9e27870d24ac72..956dc87cb07559038a63cec0b5174cec
  // Updates the cursor clip region. Used for mouse locking.
  void UpdateMouseLockRegion(aura::Window* window, bool locked) {
    if (!locked) {
-@@ -329,9 +346,14 @@ bool DesktopWindowTreeHostWin::IsVisible() const {
+@@ -333,9 +350,14 @@ bool DesktopWindowTreeHostWin::IsVisible() const {
  }
  
  void DesktopWindowTreeHostWin::SetSize(const gfx::Size& size) {
@@ -111,7 +111,7 @@ index d58b59288d881a2d74ea357f1e9e27870d24ac72..956dc87cb07559038a63cec0b5174cec
  }
  
  void DesktopWindowTreeHostWin::StackAbove(aura::Window* window) {
-@@ -346,30 +368,40 @@ void DesktopWindowTreeHostWin::StackAtTop() {
+@@ -350,30 +372,40 @@ void DesktopWindowTreeHostWin::StackAtTop() {
  }
  
  void DesktopWindowTreeHostWin::CenterWindow(const gfx::Size& size) {
@@ -154,7 +154,7 @@ index d58b59288d881a2d74ea357f1e9e27870d24ac72..956dc87cb07559038a63cec0b5174cec
    return display::win::GetScreenWin()->ScreenToDIPRect(GetHWND(), pixel_bounds);
  }
  
-@@ -677,37 +709,44 @@ void DesktopWindowTreeHostWin::HideImpl() {
+@@ -681,37 +713,44 @@ void DesktopWindowTreeHostWin::HideImpl() {
  // other get/set methods work in DIP.
  
  gfx::Rect DesktopWindowTreeHostWin::GetBoundsInPixels() const {
@@ -219,7 +219,7 @@ index d58b59288d881a2d74ea357f1e9e27870d24ac72..956dc87cb07559038a63cec0b5174cec
  }
  
  gfx::Rect
-@@ -917,21 +956,29 @@ int DesktopWindowTreeHostWin::GetNonClientComponent(
+@@ -921,21 +960,29 @@ int DesktopWindowTreeHostWin::GetNonClientComponent(
  
  void DesktopWindowTreeHostWin::GetWindowMask(const gfx::Size& size_px,
                                               SkPath* path) {
@@ -264,10 +264,10 @@ index d58b59288d881a2d74ea357f1e9e27870d24ac72..956dc87cb07559038a63cec0b5174cec
  }
  
 diff --git a/ui/views/widget/desktop_aura/desktop_window_tree_host_win.h b/ui/views/widget/desktop_aura/desktop_window_tree_host_win.h
-index e8acd2828ed05deefa335ce2bb461f0c3be8d7b7..0cd07fd5fb55dcc0d972de4c027fcb895d156592 100644
+index 1e30bce5ca5bf47726fd846f2f26705d52a8ce57..2529a00eb6ec30e4269f19c685997a778647bd51 100644
 --- a/ui/views/widget/desktop_aura/desktop_window_tree_host_win.h
 +++ b/ui/views/widget/desktop_aura/desktop_window_tree_host_win.h
-@@ -175,7 +175,7 @@ class VIEWS_EXPORT DesktopWindowTreeHostWin
+@@ -176,7 +176,7 @@ class VIEWS_EXPORT DesktopWindowTreeHostWin
    void ShowImpl() override;
    void HideImpl() override;
    gfx::Rect GetBoundsInPixels() const override;
@@ -276,7 +276,7 @@ index e8acd2828ed05deefa335ce2bb461f0c3be8d7b7..0cd07fd5fb55dcc0d972de4c027fcb89
    gfx::Rect GetBoundsInAcceleratedWidgetPixelCoordinates() override;
    gfx::Point GetLocationOnScreenInPixels() const override;
    void SetCapture() override;
-@@ -328,6 +328,12 @@ class VIEWS_EXPORT DesktopWindowTreeHostWin
+@@ -329,6 +329,12 @@ class VIEWS_EXPORT DesktopWindowTreeHostWin
    gfx::Vector2d window_expansion_top_left_delta_;
    gfx::Vector2d window_expansion_bottom_right_delta_;
  

patches/chromium/support_mixed_sandbox_with_zygote.patch

@@ -22,7 +22,7 @@ However, the patch would need to be reviewed by the security team, as it
 does touch a security-sensitive class.
 
 diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
-index e4df51e2fac09cd2c97bb125b9187aede4138f23..20a9e4536e722e5f0c8f5bdb55504b7c19d2a29e 100644
+index ae46fafbb67668d3c0a147cb0d8cf8fda958409a..3cda71f0b6c606b9df9b457e3f94ee7d3af051b6 100644
 --- a/content/browser/renderer_host/render_process_host_impl.cc
 +++ b/content/browser/renderer_host/render_process_host_impl.cc
 @@ -1905,6 +1905,10 @@ bool RenderProcessHostImpl::Init() {

patches/chromium/web_contents.patch

@@ -9,10 +9,10 @@ is needed for OSR.
 Originally landed in https://github.com/electron/libchromiumcontent/pull/226.
 
 diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
-index 2451f06b6b6dc96da44494da1db5e1f47654dad4..ee597638585d787617b5a1d7b9ccac6782fb93ef 100644
+index 35fe43c6ac99666d070036f7d862529ad364a359..825dd5a2cda02d88f17c04e50b05b89157439538 100644
 --- a/content/browser/web_contents/web_contents_impl.cc
 +++ b/content/browser/web_contents/web_contents_impl.cc
-@@ -4197,6 +4197,13 @@ void WebContentsImpl::Init(const WebContents::CreateParams& params,
+@@ -4209,6 +4209,13 @@ void WebContentsImpl::Init(const WebContents::CreateParams& params,
        params.main_frame_name, GetOpener(), primary_main_frame_policy,
        base::UnguessableToken::Create());
  
@@ -26,7 +26,7 @@ index 2451f06b6b6dc96da44494da1db5e1f47654dad4..ee597638585d787617b5a1d7b9ccac67
    std::unique_ptr<WebContentsViewDelegate> delegate =
        GetContentClient()->browser()->GetWebContentsViewDelegate(this);
  
-@@ -4207,6 +4214,7 @@ void WebContentsImpl::Init(const WebContents::CreateParams& params,
+@@ -4219,6 +4226,7 @@ void WebContentsImpl::Init(const WebContents::CreateParams& params,
      view_ = CreateWebContentsView(this, std::move(delegate),
                                    &render_view_host_delegate_view_);
    }
@@ -35,7 +35,7 @@ index 2451f06b6b6dc96da44494da1db5e1f47654dad4..ee597638585d787617b5a1d7b9ccac67
    CHECK(view_.get());
  
 diff --git a/content/public/browser/web_contents.h b/content/public/browser/web_contents.h
-index c7efc2aba74899b239140c77126666f571c127c3..e620d4c33e95c247495f3ed78952b8fc365cfb99 100644
+index ef60f27657953a92f720a0342c8bb08f24684b54..8d614d26117ec41dfe1ecffecbcfb2170c534c9a 100644
 --- a/content/public/browser/web_contents.h
 +++ b/content/public/browser/web_contents.h
 @@ -130,11 +130,14 @@ class PrerenderHandle;

patches/chromium/webview_fullscreen.patch

@@ -15,10 +15,10 @@ Note that we also need to manually update embedder's
 `api::WebContents::IsFullscreenForTabOrPending` value.
 
 diff --git a/content/browser/renderer_host/render_frame_host_impl.cc b/content/browser/renderer_host/render_frame_host_impl.cc
-index 6635ed3b341ffc63d80d895dc5746c79092f53ab..5a3acb372b87ed34a62478967c72aeeec83e9db9 100644
+index e76cccefbbf77fcfb886c41d501bcff4fd27be2f..d4f0278019e7d5ea43d6989b48fbefcbd5b05482 100644
 --- a/content/browser/renderer_host/render_frame_host_impl.cc
 +++ b/content/browser/renderer_host/render_frame_host_impl.cc
-@@ -8960,6 +8960,17 @@ void RenderFrameHostImpl::EnterFullscreen(
+@@ -8967,6 +8967,17 @@ void RenderFrameHostImpl::EnterFullscreen(
      }
    }
  
@@ -37,10 +37,10 @@ index 6635ed3b341ffc63d80d895dc5746c79092f53ab..5a3acb372b87ed34a62478967c72aeee
    if (had_fullscreen_token && !GetView()->HasFocus())
      GetView()->Focus();
 diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
-index ee597638585d787617b5a1d7b9ccac6782fb93ef..208fe58f95557ee103555858c2cda39e732ca991 100644
+index 825dd5a2cda02d88f17c04e50b05b89157439538..cbfa2ec56627994541548a49a4afe33b6e42c2d7 100644
 --- a/content/browser/web_contents/web_contents_impl.cc
 +++ b/content/browser/web_contents/web_contents_impl.cc
-@@ -4483,21 +4483,25 @@ KeyboardEventProcessingResult WebContentsImpl::PreHandleKeyboardEvent(
+@@ -4495,21 +4495,25 @@ KeyboardEventProcessingResult WebContentsImpl::PreHandleKeyboardEvent(
      const input::NativeWebKeyboardEvent& event) {
    OPTIONAL_TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("content.verbose"),
                          "WebContentsImpl::PreHandleKeyboardEvent");
@@ -80,7 +80,7 @@ index ee597638585d787617b5a1d7b9ccac6782fb93ef..208fe58f95557ee103555858c2cda39e
  }
  
  bool WebContentsImpl::HandleMouseEvent(const blink::WebMouseEvent& event) {
-@@ -4656,7 +4660,7 @@ void WebContentsImpl::EnterFullscreenMode(
+@@ -4668,7 +4672,7 @@ void WebContentsImpl::EnterFullscreenMode(
    OPTIONAL_TRACE_EVENT0("content", "WebContentsImpl::EnterFullscreenMode");
    DCHECK(CanEnterFullscreenMode(requesting_frame));
    DCHECK(requesting_frame->IsActive());

shell/browser/api/electron_api_web_contents.cc

@@ -1770,14 +1770,15 @@ void WebContents::RenderFrameCreated(
     return;
   }
 
-  content::RenderFrameHost::LifecycleState lifecycle_state =
+  if (render_frame_host->GetLifecycleState() ==
-      render_frame_host->GetLifecycleState();
+      content::RenderFrameHost::LifecycleState::kActive) {
-  if (lifecycle_state == content::RenderFrameHost::LifecycleState::kActive) {
     v8::Isolate* isolate = JavascriptEnvironment::GetIsolate();
-    v8::HandleScope handle_scope(isolate);
+    v8::HandleScope handle_scope{isolate};
     auto details = gin_helper::Dictionary::CreateEmpty(isolate);
     details.SetGetter("frame", render_frame_host);
     Emit("frame-created", details);
+    content::WebContents::FromRenderFrameHost(render_frame_host)
+        ->SetSupportsDraggableRegions(true);
   }
 }
 

shell/renderer/electron_render_frame_observer.cc

@@ -59,11 +59,6 @@ ElectronRenderFrameObserver::ElectronRenderFrameObserver(
       renderer_client_(renderer_client) {
   // Initialise resource for directory listing.
   net::NetModule::SetResourceProvider(NetResourceProvider);
-
-  // In Chrome, app regions are only supported in the main frame.
-  // However, we need to support draggable regions on other
-  // local frames/windows, so extend support beyond the main frame.
-  render_frame_->GetWebView()->SetSupportsDraggableRegions(true);
 }
 
 void ElectronRenderFrameObserver::DidClearWindowObject() {