cap: Implement AccentColor on ChromeOS

Wires up ChromeOS's accent color up to blink.

Bug: 1338061
Change-Id: Ifb78e44c96b8c2c59d93bb63f00a44b10effabec
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4918373
Reviewed-by: Rakina Zata Amni <rakina@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Giovanni Ortuno Urquidi <ortuno@chromium.org>
Reviewed-by: Joey Arhar <jarhar@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1209966}

content/browser/theme_helper.cc

@@ -5,6 +5,7 @@
 #include "content/browser/theme_helper.h"
 
 #include "base/no_destructor.h"
+#include "build/build_config.h"
 #include "content/browser/renderer_host/render_process_host_impl.h"
 #include "content/common/renderer.mojom.h"
 #include "ui/color/color_provider_key.h"
@@ -33,6 +34,10 @@ mojom::UpdateSystemColorInfoParamsPtr MakeUpdateSystemColorInfoParams(
   const auto& colors = native_theme->GetSystemColors();
   params->colors.insert(colors.begin(), colors.end());
 
+#if BUILDFLAG(IS_CHROMEOS)
+  params->accent_color = native_theme->user_color();
+#endif
+
   // TODO(crbug.com/1251637): We should not be using ColorProviders sourced from
   // the global NativeTheme web instance and instead have WebContents instances
   // propagate their specific ColorProviders to hosted frames.

content/common/renderer.mojom

@@ -41,6 +41,9 @@ struct UpdateSystemColorInfoParams {
   // renderer's ColorProviders.
   map<SystemThemeColor, uint32> colors;
 
+  // Accent color used by the system. Currently only set on ChromeOS.
+  uint32? accent_color;
+
   // Maps used to reconstruct ColorProvider instances in the renderer.
   map<color.mojom.RendererColorId, skia.mojom.SkColor> light_colors;
   map<color.mojom.RendererColorId, skia.mojom.SkColor> dark_colors;

content/renderer/render_thread_impl.cc

@@ -1565,9 +1565,14 @@ void RenderThreadImpl::UpdateSystemColorInfo(
     blink::ColorProvidersChanged();
   }
 
-  bool did_system_color_info_change =
-      ui::NativeTheme::GetInstanceForWeb()->UpdateSystemColorInfo(
-          params->is_dark_mode, params->forced_colors, params->colors);
+  auto* native_theme = ui::NativeTheme::GetInstanceForWeb();
+
+  bool did_system_color_info_change = native_theme->UpdateSystemColorInfo(
+      params->is_dark_mode, params->forced_colors, params->colors);
+
+  did_system_color_info_change |=
+      native_theme->user_color() != params->accent_color;
+  native_theme->set_user_color(params->accent_color);
 
   if (did_system_color_info_change) {
     // Notify blink of system color info changes. These give blink the

third_party/blink/public/platform/web_theme_engine.h

@@ -289,6 +289,10 @@ class WebThemeEngine {
     return absl::nullopt;
   }
 
+  virtual absl::optional<SkColor> GetAccentColor() const {
+    return absl::nullopt;
+  }
+
   virtual ForcedColors GetForcedColors() const { return ForcedColors::kNone; }
   virtual void OverrideForcedColorsTheme(bool is_dark_theme) {}
   virtual void SetForcedColors(const blink::ForcedColors forced_colors) {}

third_party/blink/renderer/core/layout/layout_theme.cc

@@ -864,6 +864,32 @@ void LayoutTheme::UpdateForcedColorsState() {
       ForcedColors::kNone;
 }
 
+bool LayoutTheme::IsAccentColorCustomized(
+    mojom::blink::ColorScheme color_scheme) const {
+  if (!RuntimeEnabledFeatures::CSSSystemAccentColorEnabled()) {
+    return false;
+  }
+
+  return WebThemeEngineHelper::GetNativeThemeEngine()
+      ->GetAccentColor()
+      .has_value();
+}
+
+Color LayoutTheme::GetSystemAccentColor(
+    mojom::blink::ColorScheme color_scheme) const {
+  if (!RuntimeEnabledFeatures::CSSSystemAccentColorEnabled()) {
+    return Color();
+  }
+
+  // Currently only plumbed through on ChromeOS.
+  const auto& accent_color =
+      WebThemeEngineHelper::GetNativeThemeEngine()->GetAccentColor();
+  if (!accent_color.has_value()) {
+    return Color();
+  }
+  return Color::FromSkColor(accent_color.value());
+}
+
 Color LayoutTheme::GetAccentColorOrDefault(
     mojom::blink::ColorScheme color_scheme) const {
   // This is from the kAccent color from NativeThemeBase::GetControlColor

third_party/blink/renderer/core/layout/layout_theme.h

@@ -182,15 +182,13 @@ class CORE_EXPORT LayoutTheme : public RefCounted<LayoutTheme> {
   virtual void AdjustControlPartStyle(ComputedStyleBuilder&);
 
   virtual bool IsAccentColorCustomized(
-      mojom::blink::ColorScheme color_scheme) const {
-    return false;
-  }
+      mojom::blink::ColorScheme color_scheme) const;
+
   // GetSystemAccentColor returns transparent unless there is a special value
   // from the OS color scheme.
   virtual Color GetSystemAccentColor(
-      mojom::blink::ColorScheme color_scheme) const {
-    return Color();
-  }
+      mojom::blink::ColorScheme color_scheme) const;
+
   // GetAccentColorOrDefault will return GetAccentColor if there is a value from
   // the OS, otherwise it will return the default accent color.
   Color GetAccentColorOrDefault(mojom::blink::ColorScheme color_scheme) const;

third_party/blink/renderer/platform/theme/web_theme_engine_default.cc

@@ -294,6 +294,10 @@ absl::optional<SkColor> WebThemeEngineDefault::GetSystemColor(
       NativeSystemThemeColor(system_theme_color));
 }
 
+absl::optional<SkColor> WebThemeEngineDefault::GetAccentColor() const {
+  return ui::NativeTheme::GetInstanceForWeb()->user_color();
+}
+
 #if BUILDFLAG(IS_WIN)
 // static
 void WebThemeEngineDefault::cacheScrollBarMetrics(

third_party/blink/renderer/platform/theme/web_theme_engine_default.h

@@ -33,6 +33,7 @@ class WebThemeEngineDefault : public WebThemeEngine {
   gfx::Rect NinePatchAperture(Part part) const override;
   absl::optional<SkColor> GetSystemColor(
       WebThemeEngine::SystemThemeColor system_theme_color) const override;
+  absl::optional<SkColor> GetAccentColor() const override;
 #if BUILDFLAG(IS_WIN)
   // Caches the scrollbar metrics. These are retrieved in the browser and passed
   // to the renderer in RendererPreferences because the required Windows