Decode GIF image frames on demand.

Source/core/svg/graphics/SVGImage.h

 /*
  * Copyright (C) 2006 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2009 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
@@ skipping 61 matching lines @@
 
     virtual void setContainerSize(const IntSize&);
     IntSize containerSize() const;
     virtual bool usesContainerSize() const { return true; }
     virtual void computeIntrinsicDimensions(Length& intrinsicWidth, Length& intrinsicHeight, FloatSize& intrinsicRatio);
 
     virtual bool dataChanged(bool allDataReceived);
 
     // FIXME: SVGImages are underreporting decoded sizes and will be unable
     // to prune because these functions are not implemented yet.
-    virtual void destroyDecodedData(bool) { }
-    virtual unsigned decodedSize() const { return 0; }
+    virtual void destroyDecodedData() OVERRIDE { }
+    virtual unsigned decodedSize() const OVERRIDE { return 0; }
 
     // FIXME: Implement this to be less conservative.
     virtual bool currentFrameKnownToBeOpaque() OVERRIDE { return false; }
 
     SVGImage(ImageObserver*);
     virtual void draw(GraphicsContext*, const FloatRect& fromRect, const FloatRect& toRect, ColorSpace styleColorSpace, CompositeOperator, BlendMode);
     void drawForContainer(GraphicsContext*, const FloatSize, float, const FloatRect&, const FloatRect&, ColorSpace, CompositeOperator, BlendMode);
     void drawPatternForContainer(GraphicsContext*, const FloatSize, float, const FloatRect&, const AffineTransform&, const FloatPoint&, ColorSpace,
         CompositeOperator, const FloatRect&);
 
     OwnPtr<SVGImageChromeClient> m_chromeClient;
     OwnPtr<Page> m_page;
     IntSize m_intrinsicSize;
 };
 }
 
 #endif // SVGImage_h