Implement PaintRenderingContext2D off BaseRenderingContext2D

third_party/WebKit/Source/modules/canvas2d/CanvasStyle.cpp

 /*
  * Copyright (C) 2006, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2007 Alp Toker <alp@atoker.com>
  * Copyright (C) 2008 Eric Seidel <eric@webkit.org>
  *
  * 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
@@ skipping 61 matching lines @@
         parsedColor = canvas ? currentColor(canvas) : Color::black;
         return true;
     case ParseFailed:
         return false;
     default:
         ASSERT_NOT_REACHED();
         return false;
     }
 }
 
+bool parseColorOnly(Color& parsedColor, const String& colorString)

[Justin Novosad, 2016/03/17 18:46:10]

You could have continued to used the old parseColorOrCurrentColor, which just
returned black for 'current color' in cases where there is no canvas element.
This was already covered in the spec. By taking a different behavior, you will
have to make a special case in the spec.  I don't think that is necessary. You
could just call parseColorOrCurrentColor with nullptr as the canvas parameter.

[ikilpatrick, 2016/03/17 19:15:41]

Ah. That's great. Thanks. Done.

+{
+    ColorParseResult parseResult = parseColor(parsedColor, colorString);
+    switch (parseResult) {
+    case ParsedRGBA:
+    case ParsedSystemColor:
+        return true;
+    case ParsedCurrentColor:
+    case ParseFailed:
+        return false;
+    default:
+        ASSERT_NOT_REACHED();
+        return false;
+    }
+}
+
 CanvasStyle::CanvasStyle(RGBA32 rgba)
     : m_type(ColorRGBA)
     , m_rgba(rgba)
 {
 }
 
 CanvasStyle::CanvasStyle(CanvasGradient* gradient)
     : m_type(Gradient)
     , m_gradient(gradient)
 {
@@ skipping 42 matching lines @@
     return Color::black;
 }
 
 DEFINE_TRACE(CanvasStyle)
 {
     visitor->trace(m_gradient);
     visitor->trace(m_pattern);
 }
 
 } // namespace blink