chrome: Add support for Alloy style browsers and windows (see #3681)

Split the Alloy runtime into bootstrap and style components. Support
creation of Alloy style browsers and windows with the Chrome runtime.
Chrome runtime (`--enable-chrome-runtime`) + Alloy style
(`--use-alloy-style`) supports Views (`--use-views`), native parent
(`--use-native`) and windowless rendering
(`--off-screen-rendering-enabled`).

Print preview is supported in all cases except with windowless rendering
on all platforms and native parent on MacOS. It is disabled by default
with Alloy style for legacy compatibility. Where supported it can be
enabled or disabled globally using `--[enable|disable]-print-preview` or
configured on a per-RequestContext basis using the
`printing.print_preview_disabled` preference. It also behaves as
expected when triggered via the PDF viewer print button.

Chrome runtime + Alloy style behavior differs from Alloy runtime in the
following significant ways:

- Supports Chrome error pages by default.
- DevTools popups are Chrome style only (cannot be windowless).
- The Alloy extension API will not supported.

Chrome runtime + Alloy style passes all expected Alloy ceftests except
the following:

- `DisplayTest.AutoResize` (Alloy extension API not supported)
- `DownloadTest.*` (Download API not yet supported)
- `ExtensionTest.*` (Alloy extension API not supported)

This change also adds Chrome runtime support for
CefContextMenuHandler::RunContextMenu (see #3293).

This change also explicitly blocks (and doesn't retry) FrameAttached
requests from PDF viewer and print preview excluded frames (see #3664).

Known issues specific to Chrome runtime + Alloy style:
- DevTools popup with windowless rendering doesn't load successfully.
  Use windowed rendering or remote debugging as a workaround.
- Chrome style Window with Alloy style BrowserView (`--use-alloy-style
  --use-chrome-style-window`) does not show Chrome theme changes.

To test:
- Run `ceftests --enable-chrome-runtime --use-alloy-style
       [--use-chrome-style-window] [--use-views|--use-native]
       --gtest_filter=...`
- Run `cefclient --enable-chrome-runtime --use-alloy-style
       [--use-chrome-style-window]
       [--use-views|--use-native|--off-screen-rendering-enabled]`
- Run `cefsimple --enable-chrome-runtime --use-alloy-style [--use-views]`

patch/patches/chrome_browser_context_menus.patch

@@ -1,22 +1,27 @@
 diff --git chrome/browser/renderer_context_menu/render_view_context_menu.cc chrome/browser/renderer_context_menu/render_view_context_menu.cc
-index d182bc1b7bff2..e4f54b6d2be24 100644
+index d182bc1b7bff2..e7c0d5b03ede7 100644
 --- chrome/browser/renderer_context_menu/render_view_context_menu.cc
 +++ chrome/browser/renderer_context_menu/render_view_context_menu.cc
-@@ -361,6 +361,13 @@ base::OnceCallback<void(RenderViewContextMenu*)>* GetMenuShownCallback() {
+@@ -361,6 +361,18 @@ base::OnceCallback<void(RenderViewContextMenu*)>* GetMenuShownCallback() {
    return callback.get();
  }
  
-+
 +RenderViewContextMenu::MenuCreatedCallback* GetMenuCreatedCallback() {
 +  static base::NoDestructor<RenderViewContextMenu::MenuCreatedCallback>
 +      callback;
 +  return callback.get();
 +}
++
++RenderViewContextMenu::MenuShowHandlerCallback* GetMenuShowHandlerCallback() {
++  static base::NoDestructor<RenderViewContextMenu::MenuShowHandlerCallback>
++      callback;
++  return callback.get();
++}
 +
  enum class UmaEnumIdLookupType {
    GeneralEnumId,
    ContextSpecificEnumId,
-@@ -618,6 +625,10 @@ int FindUMAEnumValueForCommand(int id, UmaEnumIdLookupType type) {
+@@ -618,6 +630,10 @@ int FindUMAEnumValueForCommand(int id, UmaEnumIdLookupType type) {
    if (ContextMenuMatcher::IsExtensionsCustomCommandId(id))
      return 1;
  
@@ -27,7 +32,7 @@ index d182bc1b7bff2..e4f54b6d2be24 100644
    id = CollapseCommandsForUMA(id);
    const auto& map = GetIdcToUmaMap(type);
    auto it = map.find(id);
-@@ -867,6 +878,14 @@ RenderViewContextMenu::RenderViewContextMenu(
+@@ -867,6 +883,14 @@ RenderViewContextMenu::RenderViewContextMenu(
    pdf_ocr_submenu_model_ = std::make_unique<ui::SimpleMenuModel>(this);
  #endif  // BUILDFLAG(ENABLE_SCREEN_AI_SERVICE)
  
@@ -42,7 +47,7 @@ index d182bc1b7bff2..e4f54b6d2be24 100644
    observers_.AddObserver(&autofill_context_menu_manager_);
  }
  
-@@ -1341,6 +1360,12 @@ void RenderViewContextMenu::InitMenu() {
+@@ -1341,6 +1365,12 @@ void RenderViewContextMenu::InitMenu() {
            autofill::PopupHidingReason::kContextMenuOpened);
      }
    }
@@ -55,7 +60,7 @@ index d182bc1b7bff2..e4f54b6d2be24 100644
  }
  
  Profile* RenderViewContextMenu::GetProfile() const {
-@@ -3564,6 +3589,12 @@ void RenderViewContextMenu::RegisterExecutePluginActionCallbackForTesting(
+@@ -3564,6 +3594,26 @@ void RenderViewContextMenu::RegisterExecutePluginActionCallbackForTesting(
    execute_plugin_action_callback_ = std::move(cb);
  }
  
@@ -64,15 +69,29 @@ index d182bc1b7bff2..e4f54b6d2be24 100644
 +    MenuCreatedCallback cb) {
 +  *GetMenuCreatedCallback() = cb;
 +}
++
++// static
++void RenderViewContextMenu::RegisterMenuShowHandlerCallback(
++    MenuShowHandlerCallback cb) {
++  *GetMenuShowHandlerCallback() = cb;
++}
++
++bool RenderViewContextMenu::UseShowHandler() {
++  auto* cb = GetMenuShowHandlerCallback();
++  if (!cb->is_null() && cb->Run(this)) {
++    return true;
++  }
++  return false;
++}
 +
  custom_handlers::ProtocolHandlerRegistry::ProtocolHandlerList
  RenderViewContextMenu::GetHandlersForLinkUrl() {
    custom_handlers::ProtocolHandlerRegistry::ProtocolHandlerList handlers =
 diff --git chrome/browser/renderer_context_menu/render_view_context_menu.h chrome/browser/renderer_context_menu/render_view_context_menu.h
-index 9634f1d7f3442..1187aec354b15 100644
+index 9634f1d7f3442..96dc5f252280c 100644
 --- chrome/browser/renderer_context_menu/render_view_context_menu.h
 +++ chrome/browser/renderer_context_menu/render_view_context_menu.h
-@@ -158,6 +158,12 @@ class RenderViewContextMenu
+@@ -158,7 +158,21 @@ class RenderViewContextMenu
    }
  #endif
  
@@ -81,11 +100,20 @@ index 9634f1d7f3442..1187aec354b15 100644
 +  using MenuCreatedCallback = base::RepeatingCallback<
 +      std::unique_ptr<RenderViewContextMenuObserver>(RenderViewContextMenu*)>;
 +  static void RegisterMenuCreatedCallback(MenuCreatedCallback cb);
++
++  // Registers a callback that will be called each time before context menu is
++  // shown. The callback should return true if the show has handled.
++  using MenuShowHandlerCallback = base::RepeatingCallback<
++      bool(RenderViewContextMenu*)>;
++  static void RegisterMenuShowHandlerCallback(MenuShowHandlerCallback cb);
 +
   protected:
++  bool UseShowHandler();
++
    Profile* GetProfile() const;
  
-@@ -470,6 +476,9 @@ class RenderViewContextMenu
+   // This may return nullptr (e.g. for WebUI dialogs). Virtual to allow tests to
+@@ -470,6 +484,9 @@ class RenderViewContextMenu
    //   built.
    bool is_protocol_submenu_valid_ = false;
  
@@ -95,8 +123,23 @@ index 9634f1d7f3442..1187aec354b15 100644
    // An observer that handles spelling suggestions, "Add to dictionary", and
    // "Use enhanced spell check" items.
    std::unique_ptr<SpellingMenuObserver> spelling_suggestions_menu_observer_;
+diff --git chrome/browser/ui/cocoa/renderer_context_menu/render_view_context_menu_mac_cocoa.mm chrome/browser/ui/cocoa/renderer_context_menu/render_view_context_menu_mac_cocoa.mm
+index b130e9768c2d6..049c5fb235d87 100644
+--- chrome/browser/ui/cocoa/renderer_context_menu/render_view_context_menu_mac_cocoa.mm
++++ chrome/browser/ui/cocoa/renderer_context_menu/render_view_context_menu_mac_cocoa.mm
+@@ -68,6 +68,10 @@ RenderViewContextMenuMacCocoa::~RenderViewContextMenuMacCocoa() {
+ }
+ 
+ void RenderViewContextMenuMacCocoa::Show() {
++  if (UseShowHandler()) {
++    return;
++  }
++
+   views::Widget* widget = views::Widget::GetTopLevelWidgetForNativeView(
+       source_web_contents_->GetNativeView());
+ 
 diff --git chrome/browser/ui/views/renderer_context_menu/render_view_context_menu_views.cc chrome/browser/ui/views/renderer_context_menu/render_view_context_menu_views.cc
-index c88a77a0b49e2..785ded198741e 100644
+index c88a77a0b49e2..d1af9a85c4ec6 100644
 --- chrome/browser/ui/views/renderer_context_menu/render_view_context_menu_views.cc
 +++ chrome/browser/ui/views/renderer_context_menu/render_view_context_menu_views.cc
 @@ -149,6 +149,9 @@ void RenderViewContextMenuViews::RunMenuAt(views::Widget* parent,
@@ -109,6 +152,17 @@ index c88a77a0b49e2..785ded198741e 100644
    // There are no formally defined accelerators we can query so we assume
    // that Ctrl+C, Ctrl+V, Ctrl+X, Ctrl-A, etc do what they normally do.
    switch (command_id) {
+@@ -385,6 +388,10 @@ void RenderViewContextMenuViews::AppendPlatformEditableItems() {
+ }
+ 
+ void RenderViewContextMenuViews::Show() {
++  if (UseShowHandler()) {
++    return;
++  }
++
+   if (base::CommandLine::ForCurrentProcess()->HasSwitch(switches::kKioskMode))
+     return;
+ 
 diff --git components/renderer_context_menu/render_view_context_menu_base.cc components/renderer_context_menu/render_view_context_menu_base.cc
 index c49b49d76d7cc..842a6fae5d8e4 100644
 --- components/renderer_context_menu/render_view_context_menu_base.cc