Make currentColor keyword in linear-gradient work

Source/core/css/CSSGradientValue.h

 /*
  * Copyright (C) 2008 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 40 matching lines @@
 // When allocated on the stack its members are found by conservative
 // stack scanning. When allocated as part of Vectors in heap-allocated
 // objects its members are visited via the containing object's
 // (CSSGradientValue) traceAfterDispatch method.
 struct CSSGradientColorStop {
     ALLOW_ONLY_INLINE_ALLOCATION();
 public:
     CSSGradientColorStop() : m_colorIsDerivedFromElement(false) { };
     RefPtrWillBeMember<CSSPrimitiveValue> m_position; // percentage or length
     RefPtrWillBeMember<CSSPrimitiveValue> m_color;
     Color m_resolvedColor;

[Timothy Loh, 2014/12/03 01:10:07]

I guess we can remove this now?

     bool m_colorIsDerivedFromElement;
     bool operator==(const CSSGradientColorStop& other) const
     {
         return compareCSSValuePtr(m_color, other.m_color)
             && compareCSSValuePtr(m_position, other.m_position);
     }
     bool isHint() const
     {
         ASSERT(m_color || m_position);
         return !m_color;
@@ skipping 56 matching lines @@
         , m_firstY(other.m_firstY)
         , m_secondX(other.m_secondX)
         , m_secondY(other.m_secondY)
         , m_stops(other.m_stops)
         , m_stopsSorted(other.m_stopsSorted)
         , m_gradientType(gradientType)
         , m_repeating(other.isRepeating() ? Repeating : NonRepeating)
     {
     }
 
-    void addStops(Gradient*, const CSSToLengthConversionData&, float maxLengthForRepeat = 0);
+    void addStops(Gradient*, const CSSToLengthConversionData&, float maxLengthForRepeat, const RenderObject&);
 
     // Resolve points/radii to front end values.
     FloatPoint computeEndPoint(CSSPrimitiveValue*, CSSPrimitiveValue*, const CSSToLengthConversionData&, const IntSize&);
 
     bool isCacheable() const;
 
     // Points. Some of these may be null.
     RefPtrWillBeMember<CSSPrimitiveValue> m_firstX;
     RefPtrWillBeMember<CSSPrimitiveValue> m_firstY;
 
@@ skipping 15 matching lines @@
     static PassRefPtrWillBeRawPtr<CSSLinearGradientValue> create(CSSGradientRepeat repeat, CSSGradientType gradientType = CSSLinearGradient)
     {
         return adoptRefWillBeNoop(new CSSLinearGradientValue(repeat, gradientType));
     }
 
     void setAngle(PassRefPtrWillBeRawPtr<CSSPrimitiveValue> val) { m_angle = val; }
 
     String customCSSText() const;
 
     // Create the gradient for a given size.
-    PassRefPtr<Gradient> createGradient(const CSSToLengthConversionData&, const IntSize&);
+    PassRefPtr<Gradient> createGradient(const CSSToLengthConversionData&, const IntSize&, const RenderObject&);
 
     PassRefPtrWillBeRawPtr<CSSLinearGradientValue> clone() const
     {
         return adoptRefWillBeNoop(new CSSLinearGradientValue(*this));
     }
 
     bool equals(const CSSLinearGradientValue&) const;
 
     void traceAfterDispatch(Visitor*);
 
@@ skipping 31 matching lines @@
     void setFirstRadius(PassRefPtrWillBeRawPtr<CSSPrimitiveValue> val) { m_firstRadius = val; }
     void setSecondRadius(PassRefPtrWillBeRawPtr<CSSPrimitiveValue> val) { m_secondRadius = val; }
 
     void setShape(PassRefPtrWillBeRawPtr<CSSPrimitiveValue> val) { m_shape = val; }
     void setSizingBehavior(PassRefPtrWillBeRawPtr<CSSPrimitiveValue> val) { m_sizingBehavior = val; }
 
     void setEndHorizontalSize(PassRefPtrWillBeRawPtr<CSSPrimitiveValue> val) { m_endHorizontalSize = val; }
     void setEndVerticalSize(PassRefPtrWillBeRawPtr<CSSPrimitiveValue> val) { m_endVerticalSize = val; }
 
     // Create the gradient for a given size.
-    PassRefPtr<Gradient> createGradient(const CSSToLengthConversionData&, const IntSize&);
+    PassRefPtr<Gradient> createGradient(const CSSToLengthConversionData&, const IntSize&, const RenderObject&);
 
     bool equals(const CSSRadialGradientValue&) const;
 
     void traceAfterDispatch(Visitor*);
 
 private:
     CSSRadialGradientValue(CSSGradientRepeat repeat, CSSGradientType gradientType = CSSRadialGradient)
         : CSSGradientValue(RadialGradientClass, repeat, gradientType)
     {
     }
@@ skipping 23 matching lines @@
 
     RefPtrWillBeMember<CSSPrimitiveValue> m_endHorizontalSize;
     RefPtrWillBeMember<CSSPrimitiveValue> m_endVerticalSize;
 };
 
 DEFINE_CSS_VALUE_TYPE_CASTS(CSSRadialGradientValue, isRadialGradientValue());
 
 } // namespace blink
 
 #endif // CSSGradientValue_h