views: Support themes for Alloy BrowserView in Chrome Window (see #3681)

To test:
- Run `cefclient --enable-chrome-runtime --use-alloy-style
                 --use-chrome-style-window [--background-color=green]`
- OS and Chrome theme changes behave as expected.

libcef/browser/chrome/views/chrome_browser_frame.cc

@@ -8,6 +8,7 @@
 #include "cef/libcef/browser/thread_util.h"
 #include "cef/libcef/browser/views/window_view.h"
 #include "chrome/browser/themes/theme_service.h"
+#include "chrome/browser/themes/theme_service_factory.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_commands.h"
 #include "chrome/browser/ui/views/frame/browser_view.h"
@@ -21,6 +22,10 @@
 ChromeBrowserFrame::ChromeBrowserFrame(CefWindowView* window_view)
     : window_view_(window_view) {}
 
+ChromeBrowserFrame::~ChromeBrowserFrame() {
+  DCHECK(associated_profiles_.empty());
+}
+
 void ChromeBrowserFrame::Init(BrowserView* browser_view,
                               std::unique_ptr<Browser> browser) {
   DCHECK(browser_view);
@@ -63,17 +68,71 @@ void ChromeBrowserFrame::Initialized() {
 #endif
 }
 
-void ChromeBrowserFrame::AddAssociatedProfile(Profile* /*profile*/) {
+void ChromeBrowserFrame::AddAssociatedProfile(Profile* profile) {
-  // Calls ThemeChanged().
+  DCHECK(profile);
-  UserChangedTheme(BrowserThemeChangeType::kBrowserTheme);
+
+  // Always call ThemeChanged() when the Chrome style BrowserView is added.
+  bool call_theme_changed =
+      browser_view_ && browser_view_->GetProfile() == profile;
+
+  ProfileMap::iterator it = associated_profiles_.find(profile);
+  if (it != associated_profiles_.end()) {
+    // Another instance of a known Profile.
+    (it->second)++;
+  } else {
+    auto* current_profile = GetThemeProfile();
+
+    associated_profiles_.insert(std::make_pair(profile, 1));
+
+    if (auto* theme_service = ThemeServiceFactory::GetForProfile(profile)) {
+      theme_service->AddObserver(this);
+    }
+
+    // Potentially switching to a different theme.
+    call_theme_changed |= GetThemeProfile() != current_profile;
+  }
+
+  if (call_theme_changed) {
+    // Calls ThemeChanged().
+    UserChangedTheme(BrowserThemeChangeType::kBrowserTheme);
+  }
 }
 
-void ChromeBrowserFrame::RemoveAssociatedProfile(Profile* /*profile*/) {}
+void ChromeBrowserFrame::RemoveAssociatedProfile(Profile* profile) {
+  DCHECK(profile);
+  ProfileMap::iterator it = associated_profiles_.find(profile);
+  if (it == associated_profiles_.end()) {
+    DCHECK(false);  // Not reached.
+    return;
+  }
+  if (--(it->second) > 0) {
+    // More instances of the Profile exist.
+    return;
+  }
+
+  auto* current_profile = GetThemeProfile();
+
+  associated_profiles_.erase(it);
+
+  if (auto* theme_service = ThemeServiceFactory::GetForProfile(profile)) {
+    theme_service->RemoveObserver(this);
+  }
+
+  auto* new_profile = GetThemeProfile();
+  if (new_profile != current_profile) {
+    // Switching to a different theme.
+    NotifyThemeColorsChanged(/*chrome_theme=*/!!new_profile);
+  }
+}
 
 Profile* ChromeBrowserFrame::GetThemeProfile() const {
+  // Always prefer the Browser Profile, if any.
   if (browser_view_) {
     return browser_view_->GetProfile();
   }
+  if (!associated_profiles_.empty()) {
+    return associated_profiles_.begin()->first;
+  }
   return nullptr;
 }
 
@@ -147,6 +206,31 @@ void ChromeBrowserFrame::OnNativeThemeUpdated(ui::NativeTheme* observed_theme) {
   native_theme_change_ = false;
 }
 
+ui::ColorProviderKey ChromeBrowserFrame::GetColorProviderKey() const {
+  if (browser_view_) {
+    // Use the default Browser implementation.
+    return BrowserFrame::GetColorProviderKey();
+  }
+
+  const auto& widget_key = Widget::GetColorProviderKey();
+  if (auto* profile = GetThemeProfile()) {
+    return CefWidget::GetColorProviderKey(widget_key, profile);
+  }
+  return widget_key;
+}
+
+void ChromeBrowserFrame::OnThemeChanged() {
+  if (browser_view_) {
+    // Ignore these notifications if we have a Browser.
+    return;
+  }
+
+  // When the Chrome theme changes, the NativeTheme may also change.
+  SelectNativeTheme();
+
+  NotifyThemeColorsChanged(/*chrome_theme=*/true);
+}
+
 void ChromeBrowserFrame::OnColorProviderCacheResetMissed() {
   // Ignore calls during Widget::Init().
   if (!initialized_) {

libcef/browser/chrome/views/chrome_browser_frame.h

@@ -6,9 +6,12 @@
 #define CEF_LIBCEF_BROWSER_CHROME_VIEWS_CHROME_BROWSER_FRAME_H_
 #pragma once
 
+#include <map>
+
 #include "base/memory/weak_ptr.h"
 #include "cef/libcef/browser/views/color_provider_tracker.h"
 #include "cef/libcef/browser/views/widget.h"
+#include "chrome/browser/themes/theme_service_observer.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/views/frame/browser_frame.h"
 
@@ -95,9 +98,11 @@ class CefWindowView;
 // CefWindowView::CreateWidget() when the Chrome runtime is enabled.
 class ChromeBrowserFrame : public BrowserFrame,
                            public CefWidget,
-                           public CefColorProviderTracker::Observer {
+                           public CefColorProviderTracker::Observer,
+                           public ThemeServiceObserver {
  public:
   explicit ChromeBrowserFrame(CefWindowView* window_view);
+  ~ChromeBrowserFrame() override;
 
   ChromeBrowserFrame(const ChromeBrowserFrame&) = delete;
   ChromeBrowserFrame& operator=(const ChromeBrowserFrame&) = delete;
@@ -130,6 +135,10 @@ class ChromeBrowserFrame : public BrowserFrame,
 
   // ui::NativeThemeObserver methods:
   void OnNativeThemeUpdated(ui::NativeTheme* observed_theme) override;
+  ui::ColorProviderKey GetColorProviderKey() const override;
+
+  // ThemeServiceObserver methods:
+  void OnThemeChanged() override;
 
   BrowserView* browser_view() const { return browser_view_; }
 
@@ -145,6 +154,10 @@ class ChromeBrowserFrame : public BrowserFrame,
   bool initialized_ = false;
   bool native_theme_change_ = false;
 
+  // Map of Profile* to count.
+  using ProfileMap = std::map<Profile*, size_t>;
+  ProfileMap associated_profiles_;
+
   CefColorProviderTracker color_provider_tracker_{this};
 
   base::WeakPtrFactory<ChromeBrowserFrame> weak_ptr_factory_{this};

libcef/browser/views/widget.cc

@@ -8,6 +8,26 @@
 #include "cef/libcef/browser/views/view_util.h"
 #include "cef/libcef/browser/views/widget_impl.h"
 #include "cef/libcef/browser/views/window_impl.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/themes/theme_service.h"
+#include "chrome/browser/themes/theme_service_factory.h"
+
+namespace {
+
+ui::ColorProviderKey::SchemeVariant GetSchemeVariant(
+    ui::mojom::BrowserColorVariant color_variant) {
+  using BCV = ui::mojom::BrowserColorVariant;
+  using SV = ui::ColorProviderKey::SchemeVariant;
+  static constexpr auto kSchemeVariantMap = base::MakeFixedFlatMap<BCV, SV>({
+      {BCV::kTonalSpot, SV::kTonalSpot},
+      {BCV::kNeutral, SV::kNeutral},
+      {BCV::kVibrant, SV::kVibrant},
+      {BCV::kExpressive, SV::kExpressive},
+  });
+  return kSchemeVariantMap.at(color_variant);
+}
+
+}  // namespace
 
 // static
 CefWidget* CefWidget::Create(CefWindowView* window_view) {
@@ -30,3 +50,60 @@ CefWidget* CefWidget::GetForWidget(views::Widget* widget) {
   }
   return nullptr;
 }
+
+// static
+ui::ColorProviderKey CefWidget::GetColorProviderKey(
+    const ui::ColorProviderKey& widget_key,
+    Profile* profile) {
+  // Based on BrowserFrame::GetColorProviderKey.
+  auto key = widget_key;
+
+  const auto* theme_service = ThemeServiceFactory::GetForProfile(profile);
+  CHECK(theme_service);
+
+  // color_mode.
+  [&key, theme_service]() {
+    const auto browser_color_scheme = theme_service->GetBrowserColorScheme();
+    if (browser_color_scheme != ThemeService::BrowserColorScheme::kSystem) {
+      key.color_mode =
+          browser_color_scheme == ThemeService::BrowserColorScheme::kLight
+              ? ui::ColorProviderKey::ColorMode::kLight
+              : ui::ColorProviderKey::ColorMode::kDark;
+    }
+  }();
+
+  // user_color.
+  // Device theme retains the user_color from `Widget`.
+  if (!theme_service->UsingDeviceTheme()) {
+    if (theme_service->UsingAutogeneratedTheme()) {
+      key.user_color = theme_service->GetAutogeneratedThemeColor();
+    } else if (auto user_color = theme_service->GetUserColor()) {
+      key.user_color = user_color;
+    }
+  }
+
+  // user_color_source.
+  if (theme_service->UsingDeviceTheme()) {
+    key.user_color_source = ui::ColorProviderKey::UserColorSource::kAccent;
+  } else if (theme_service->GetIsGrayscale()) {
+    key.user_color_source = ui::ColorProviderKey::UserColorSource::kGrayscale;
+  } else if (theme_service->GetIsBaseline()) {
+    key.user_color_source = ui::ColorProviderKey::UserColorSource::kBaseline;
+  } else {
+    CHECK(key.user_color.has_value());
+    key.user_color_source = ui::ColorProviderKey::UserColorSource::kAccent;
+  }
+
+  // scheme_variant.
+  ui::mojom::BrowserColorVariant color_variant =
+      theme_service->GetBrowserColorVariant();
+  if (!theme_service->UsingDeviceTheme() &&
+      color_variant != ui::mojom::BrowserColorVariant::kSystem) {
+    key.scheme_variant = GetSchemeVariant(color_variant);
+  }
+
+  // frame_type.
+  key.frame_type = ui::ColorProviderKey::FrameType::kNative;
+
+  return key;
+}

libcef/browser/views/widget.h

@@ -6,6 +6,8 @@
 #define CEF_LIBCEF_BROWSER_VIEWS_WIDGET_H_
 #pragma once
 
+#include "ui/color/color_provider_key.h"
+
 class CefWindowView;
 class Profile;
 
@@ -42,7 +44,6 @@ class CefWidget {
 
   // Track all Profiles associated with this Widget. Called from
   // CefBrowserViewImpl::AddedToWidget and DisassociateFromWidget.
-  // |profile| is only used with the Alloy runtime.
   virtual void AddAssociatedProfile(Profile* profile) = 0;
   virtual void RemoveAssociatedProfile(Profile* profile) = 0;
 
@@ -59,6 +60,10 @@ class CefWidget {
 
  protected:
   virtual ~CefWidget() = default;
+
+  static ui::ColorProviderKey GetColorProviderKey(
+      const ui::ColorProviderKey& widget_key,
+      Profile* profile);
 };
 
 #endif  // CEF_LIBCEF_BROWSER_VIEWS_WIDGET_H_

libcef/browser/views/widget_impl.cc

@@ -15,23 +15,6 @@
 #include "ui/linux/linux_ui.h"
 #endif
 
-namespace {
-
-ui::ColorProviderKey::SchemeVariant GetSchemeVariant(
-    ui::mojom::BrowserColorVariant color_variant) {
-  using BCV = ui::mojom::BrowserColorVariant;
-  using SV = ui::ColorProviderKey::SchemeVariant;
-  static constexpr auto kSchemeVariantMap = base::MakeFixedFlatMap<BCV, SV>({
-      {BCV::kTonalSpot, SV::kTonalSpot},
-      {BCV::kNeutral, SV::kNeutral},
-      {BCV::kVibrant, SV::kVibrant},
-      {BCV::kExpressive, SV::kExpressive},
-  });
-  return kSchemeVariantMap.at(color_variant);
-}
-
-}  // namespace
-
 CefWidgetImpl::CefWidgetImpl(CefWindowView* window_view)
     : window_view_(window_view) {}
 
@@ -156,62 +139,11 @@ void CefWidgetImpl::OnNativeThemeUpdated(ui::NativeTheme* observed_theme) {
 }
 
 ui::ColorProviderKey CefWidgetImpl::GetColorProviderKey() const {
-  auto* profile = GetThemeProfile();
+  const auto& widget_key = Widget::GetColorProviderKey();
-  if (!profile) {
+  if (auto* profile = GetThemeProfile()) {
-    return Widget::GetColorProviderKey();
+    return CefWidget::GetColorProviderKey(widget_key, profile);
   }
-
+  return widget_key;
-  // Based on BrowserFrame::GetColorProviderKey.
-  auto key = Widget::GetColorProviderKey();
-
-  const auto* theme_service = ThemeServiceFactory::GetForProfile(profile);
-  CHECK(theme_service);
-
-  // color_mode.
-  [&key, theme_service]() {
-    const auto browser_color_scheme = theme_service->GetBrowserColorScheme();
-    if (browser_color_scheme != ThemeService::BrowserColorScheme::kSystem) {
-      key.color_mode =
-          browser_color_scheme == ThemeService::BrowserColorScheme::kLight
-              ? ui::ColorProviderKey::ColorMode::kLight
-              : ui::ColorProviderKey::ColorMode::kDark;
-    }
-  }();
-
-  // user_color.
-  // Device theme retains the user_color from `Widget`.
-  if (!theme_service->UsingDeviceTheme()) {
-    if (theme_service->UsingAutogeneratedTheme()) {
-      key.user_color = theme_service->GetAutogeneratedThemeColor();
-    } else if (auto user_color = theme_service->GetUserColor()) {
-      key.user_color = user_color;
-    }
-  }
-
-  // user_color_source.
-  if (theme_service->UsingDeviceTheme()) {
-    key.user_color_source = ui::ColorProviderKey::UserColorSource::kAccent;
-  } else if (theme_service->GetIsGrayscale()) {
-    key.user_color_source = ui::ColorProviderKey::UserColorSource::kGrayscale;
-  } else if (theme_service->GetIsBaseline()) {
-    key.user_color_source = ui::ColorProviderKey::UserColorSource::kBaseline;
-  } else {
-    CHECK(key.user_color.has_value());
-    key.user_color_source = ui::ColorProviderKey::UserColorSource::kAccent;
-  }
-
-  // scheme_variant.
-  ui::mojom::BrowserColorVariant color_variant =
-      theme_service->GetBrowserColorVariant();
-  if (!theme_service->UsingDeviceTheme() &&
-      color_variant != ui::mojom::BrowserColorVariant::kSystem) {
-    key.scheme_variant = GetSchemeVariant(color_variant);
-  }
-
-  // frame_type.
-  key.frame_type = ui::ColorProviderKey::FrameType::kNative;
-
-  return key;
 }
 
 void CefWidgetImpl::OnThemeChanged() {

patch/patches/chrome_runtime_views.patch

@@ -233,7 +233,7 @@ index 0ccfe39eb5696..c9424316b6d14 100644
      return gfx::Rect();
    }
 diff --git chrome/browser/ui/views/frame/browser_frame.cc chrome/browser/ui/views/frame/browser_frame.cc
-index 8dd3620ba2720..ab3a92fd7ebe4 100644
+index 8dd3620ba2720..e3bac8207de24 100644
 --- chrome/browser/ui/views/frame/browser_frame.cc
 +++ chrome/browser/ui/views/frame/browser_frame.cc
 @@ -114,15 +114,23 @@ ui::ColorProviderKey::SchemeVariant GetSchemeVariant(
@@ -332,16 +332,7 @@ index 8dd3620ba2720..ab3a92fd7ebe4 100644
    chrome::SaveWindowWorkspace(browser_view_->browser(), GetWorkspace());
    chrome::SaveWindowVisibleOnAllWorkspaces(browser_view_->browser(),
                                             IsVisibleOnAllWorkspaces());
-@@ -483,6 +515,8 @@ void BrowserFrame::OnNativeThemeUpdated(ui::NativeTheme* observed_theme) {
+@@ -572,6 +604,13 @@ void BrowserFrame::SelectNativeTheme() {
- 
- ui::ColorProviderKey BrowserFrame::GetColorProviderKey() const {
-   auto key = Widget::GetColorProviderKey();
-+  if (!browser_view_)
-+    return key;
- 
-   key.app_controller = browser_view_->browser()->app_controller();
- 
-@@ -572,6 +606,13 @@ void BrowserFrame::SelectNativeTheme() {
      return;
    }
  
@@ -355,7 +346,7 @@ index 8dd3620ba2720..ab3a92fd7ebe4 100644
    // Ignore the system theme for web apps with window-controls-overlay as the
    // display_override so the web contents can blend with the overlay by using
    // the developer-provided theme color for a better experience. Context:
-@@ -637,5 +678,8 @@ bool BrowserFrame::RegenerateFrameOnThemeChange(
+@@ -637,5 +676,8 @@ bool BrowserFrame::RegenerateFrameOnThemeChange(
  }
  
  bool BrowserFrame::IsIncognitoBrowser() const {