JPEGImageDecoder RGB565 and downsample support and related Skia imagegenerator changes

third_party/WebKit/Source/platform/image-decoders/ImageDecoder.h

Index: third_party/WebKit/Source/platform/image-decoders/ImageDecoder.h
diff --git a/third_party/WebKit/Source/platform/image-decoders/ImageDecoder.h b/third_party/WebKit/Source/platform/image-decoders/ImageDecoder.h
index 3507ba973494c3a0b1c81c87265749efa17ac94b..3f484c031691fd5cf2f067b31a1f4c60b4319542 100644
--- a/third_party/WebKit/Source/platform/image-decoders/ImageDecoder.h
+++ b/third_party/WebKit/Source/platform/image-decoders/ImageDecoder.h
@@ -292,6 +292,8 @@ public:
     virtual bool canDecodeToYUV() { return false; }
     virtual bool decodeToYUV() { return false; }
     virtual void setImagePlanes(PassOwnPtr<ImagePlanes>) { }
+    virtual bool canDecodeToRGB565() { return false; }
+    virtual bool setDecodeRGB565Enabled(const bool enable) { return false; }
 
 protected:
     // Calculates the most recent frame whose image data may be needed in