JPEGImageDecoder RGB565 and downsample support and related Skia imagegenerator changes

third_party/WebKit/Source/platform/graphics/DecodingImageGenerator.h

 /*
  * 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:
  *
  * 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 42 matching lines @@
     void setGenerationId(size_t id) { m_generationId = id; }
 
 protected:
     SkData* onRefEncodedData() override;
 
     bool onGetPixels(const SkImageInfo&, void* pixels, size_t rowBytes,
         SkPMColor ctable[], int* ctableCount) override;
 
     bool onGetYUV8Planes(SkISize sizes[3], void* planes[3], size_t rowBytes[3], SkYUVColorSpace*) override;
 
+    bool onCanDecodeAndScale(const SkColorType targetType, const SkScalar scale,
+        SkISize *availableSize, SkISize *lowerSize) override;
+
+
 private:
     RefPtr<ImageFrameGenerator> m_frameGenerator;
     size_t m_frameIndex;
     size_t m_generationId;
 };
 
 } // namespace blink
 
 #endif // DecodingImageGenerator_h_