Cleanup some dead code in blink::ImageBuffer and friends

third_party/WebKit/Source/platform/graphics/ImageBufferSurface.cpp

 /*
  * 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 63 matching lines @@
 void ImageBufferSurface::draw(GraphicsContext* context, const FloatRect& destRect, const FloatRect& srcRect, SkXfermode::Mode op)
 {
     RefPtr<SkImage> snapshot = newImageSnapshot(PreferNoAcceleration);
     if (!snapshot)
         return;
 
     RefPtr<Image> image = StaticBitmapImage::create(snapshot.release());
     context->drawImage(image.get(), destRect, srcRect, op);
 }
 
-const SkBitmap& ImageBufferSurface::deprecatedBitmapForOverwrite()
-{
-    ASSERT_NOT_REACHED(); // should only be called on non-accelerated surface types, which have overrides
-    return canvas()->getDevice()->accessBitmap(false); // Because we have to return something for the code to compile, and it can't be a local (by address).
-}
-
-
 void ImageBufferSurface::flush()
 {
     canvas()->flush();
 }
 
 bool ImageBufferSurface::writePixels(const SkImageInfo& origInfo, const void* pixels, size_t rowBytes, int x, int y)
 {
     return canvas()->writePixels(origInfo, pixels, rowBytes, x, y);
 }
 
 } // namespace blink