Store the color and keyword in StyleColor for system colors

While CSSSystemColorComputeToSelf is under development, store the
color and keyword associated with a system color in StyleColor. This
will allow Forced Colors Mode to access the system color keyword until
CSSSystemColorComputeToSelf is enabled by default.

Bug: 970285,1081945
Change-Id: Idbf3d2ba0960574faace503d79afd9e55f405d1c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2373268
Commit-Queue: Alison Maher <almaher@microsoft.com>
Reviewed-by: Kevin Babbitt <kbabbitt@microsoft.com>
Reviewed-by: Anders Hartvoll Ruud <andruud@chromium.org>
Cr-Commit-Position: refs/heads/master@{#801870}

third_party/blink/renderer/core/css/resolver/style_builder_converter.cc

@@ -1549,8 +1549,11 @@ StyleColor StyleBuilderConverter::ConvertStyleColor(StyleResolverState& state,
       return StyleColor::CurrentColor();
     if (StyleColor::IsSystemColor(value_id)) {
       CountSystemColorComputeToSelfUsage(state);
-      if (RuntimeEnabledFeatures::CSSSystemColorComputeToSelfEnabled())
-        return StyleColor(value_id);
+      return StyleColor(
+          state.GetDocument().GetTextLinkColors().ColorFromCSSValue(
+              value, Color(), state.Style()->UsedColorScheme(),
+              for_visited_link),
+          value_id);
     }
   }
   return StyleColor(state.GetDocument().GetTextLinkColors().ColorFromCSSValue(

third_party/blink/renderer/core/css/style_color.cc

@@ -5,6 +5,7 @@
 #include "third_party/blink/renderer/core/css/style_color.h"
 
 #include "third_party/blink/renderer/core/layout/layout_theme.h"
+#include "third_party/blink/renderer/platform/runtime_enabled_features.h"
 
 namespace blink {
 
@@ -12,7 +13,7 @@ Color StyleColor::Resolve(Color current_color,
                           WebColorScheme color_scheme) const {
   if (IsCurrentColor())
     return current_color;
-  if (color_keyword_ != CSSValueID::kInvalid)
+  if (EffectiveColorKeyword() != CSSValueID::kInvalid)
     return ColorFromKeyword(color_keyword_, color_scheme);
   return color_;
 }
@@ -60,4 +61,12 @@ bool StyleColor::IsSystemColor(CSSValueID id) {
          id == CSSValueID::kMenu;
 }
 
+CSSValueID StyleColor::EffectiveColorKeyword() const {
+  if (!RuntimeEnabledFeatures::CSSSystemColorComputeToSelfEnabled()) {
+    return IsSystemColor(color_keyword_) ? CSSValueID::kInvalid
+                                         : color_keyword_;
+  }
+  return color_keyword_;
+}
+
 }  // namespace blink

third_party/blink/renderer/core/css/style_color.h

@@ -32,22 +32,30 @@
 #define THIRD_PARTY_BLINK_RENDERER_CORE_CSS_STYLE_COLOR_H_
 
 #include "third_party/blink/public/platform/web_color_scheme.h"
+#include "third_party/blink/renderer/core/core_export.h"
 #include "third_party/blink/renderer/core/css_value_keywords.h"
 #include "third_party/blink/renderer/platform/graphics/color.h"
 #include "third_party/blink/renderer/platform/wtf/allocator/allocator.h"
 
 namespace blink {
 
-class StyleColor {
+class CORE_EXPORT StyleColor {
   DISALLOW_NEW();
 
  public:
-  StyleColor() : color_keyword_(CSSValueID::kCurrentcolor) {}
+  StyleColor() = default;
   explicit StyleColor(Color color)
       : color_(color), color_keyword_(CSSValueID::kInvalid) {}
   explicit StyleColor(RGBA32 color)
       : color_(color), color_keyword_(CSSValueID::kInvalid) {}
   explicit StyleColor(CSSValueID keyword) : color_keyword_(keyword) {}
+  // TODO(1081945): We need to store the color and keyword for system colors
+  // to allow forced colors mode to access system color keywords while the
+  // CSSSystemColorComputeToSelf feature is under development. Once
+  // CSSSystemColorComputeToSelf is enabled, we can remove this ctr and
+  // EffectiveColorKeyword() and use color_keyword_ directly, instead.
+  StyleColor(Color color, CSSValueID keyword)
+      : color_(color), color_keyword_(keyword) {}
   static StyleColor CurrentColor() { return StyleColor(); }
 
   bool IsCurrentColor() const {
@@ -80,11 +88,15 @@ class StyleColor {
   inline bool IsValid() const {
     // At least one of color_keyword_ and color_ should retain its default
     // value.
-    return color_keyword_ == CSSValueID::kInvalid || color_ == Color();
+    return EffectiveColorKeyword() == CSSValueID::kInvalid ||
+           color_ == Color() || IsSystemColor(EffectiveColorKeyword());
   }
 
   Color color_;
-  CSSValueID color_keyword_;
+  CSSValueID color_keyword_ = CSSValueID::kCurrentcolor;
+
+ private:
+  CSSValueID EffectiveColorKeyword() const;
 };
 
 }  // namespace blink