[css-ui] Add support for caret-color property

third_party/WebKit/Source/core/css/StyleColor.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 23 matching lines @@
 #include "core/CSSValueKeywords.h"
 #include "platform/graphics/Color.h"
 #include "wtf/Allocator.h"
 
 namespace blink {
 
 class StyleColor {
   DISALLOW_NEW();
 
  public:
-  StyleColor() : m_currentColor(true) {}
-  StyleColor(Color color) : m_color(color), m_currentColor(false) {}
+  StyleColor() : m_type(CurrentColor) {}
+  StyleColor(Color color) : m_color(color), m_type(SpecifiedColor) {}
   static StyleColor currentColor() { return StyleColor(); }
+  static StyleColor autoColor() { return StyleColor(AutoColor); }
 
-  bool isCurrentColor() const { return m_currentColor; }
+  bool isAutoColor() const { return m_type == AutoColor; }
+  bool isCurrentColor() const { return m_type == CurrentColor; }
   Color getColor() const {
-    ASSERT(!isCurrentColor());
+    DCHECK(!isAutoColor());
+    DCHECK(!isCurrentColor());
     return m_color;
   }
 
   Color resolve(Color currentColor) const {
-    return m_currentColor ? currentColor : m_color;
+    return m_type == SpecifiedColor ? m_color : currentColor;
   }
 
   static Color colorFromKeyword(CSSValueID);
   static bool isColorKeyword(CSSValueID);
   static bool isSystemColor(CSSValueID);
 
  private:
+  enum ColorType { AutoColor, CurrentColor, SpecifiedColor };

[Timothy Loh, 2016/11/22 02:17:35]

I'd prefer if we didn't add Auto to StyleColor. This class is intended to map
directly to a <color> type. Maybe make a separate class (or can we get away with
not adding a new class at all?)

[yosin_UTC9, 2016/11/22 02:25:10]

nit: Let's use |enum class|.

|ColorType| is ambiguous. How about |ValueType|?
e.g. enum ValueType { Auto, CurrentColor, Numeric };
According to the spce, <color> = currentColor | transparent | RGB | HSL | ...

[Manuel Rego, 2016/11/22 09:36:01]

I can create a different class, but I don't see how we can manage "auto"
without having a specific class for this.

Specifically I'm wondering how we could return "auto" as computed value,
if we don't store it using something like this.
The spec is clear about caret-color returning "auto" as computed value.

[Manuel Rego, 2016/11/22 09:36:01]

Good suggestion, anyway as @timloh suggested I can move this
to a different class.

+  StyleColor(ColorType type) : m_type(type) {}
   Color m_color;
-  bool m_currentColor;
+  ColorType m_type;
 };
 
 inline bool operator==(const StyleColor& a, const StyleColor& b) {
   if (a.isCurrentColor() || b.isCurrentColor())
     return a.isCurrentColor() && b.isCurrentColor();
+  if (a.isAutoColor() || b.isAutoColor())
+    return a.isAutoColor() && b.isAutoColor();
   return a.getColor() == b.getColor();
 }
 
 inline bool operator!=(const StyleColor& a, const StyleColor& b) {
   return !(a == b);
 }
 
 }  // namespace blink
 
 #endif  // StyleColor_h