Cleanup namespace usage in platform/graphics/[G-S]*

Source/platform/graphics/GradientGeneratedImage.h

 /*
  * Copyright (C) 2008, 2012 Apple Computer, 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 30 matching lines @@
     {
         return adoptRef(new GradientGeneratedImage(generator, size));
     }
 
     virtual ~GradientGeneratedImage()
     {
     }
 
 protected:
     virtual void draw(GraphicsContext*, const FloatRect&, const FloatRect&,
-        CompositeOperator, blink::WebBlendMode) OVERRIDE;
+        CompositeOperator, WebBlendMode) OVERRIDE;
     virtual void drawPattern(GraphicsContext*, const FloatRect&,
         const FloatSize&, const FloatPoint&, CompositeOperator,
-        const FloatRect&, blink::WebBlendMode, const IntSize& repeatSpacing) OVERRIDE;
+        const FloatRect&, WebBlendMode, const IntSize& repeatSpacing) OVERRIDE;
 
     GradientGeneratedImage(PassRefPtr<Gradient> generator, const IntSize& size)
         : m_gradient(generator)
     {
         m_size = size;
     }
 
     RefPtr<Gradient> m_gradient;
 };
 
-}
+} // namespace blink
 
 #endif