JPEGImageDecoder RGB565 and downsample support and related Skia imagegenerator changes

third_party/WebKit/Source/platform/image-decoders/jpeg/JPEGImageDecoder.h

Index: third_party/WebKit/Source/platform/image-decoders/jpeg/JPEGImageDecoder.h
diff --git a/third_party/WebKit/Source/platform/image-decoders/jpeg/JPEGImageDecoder.h b/third_party/WebKit/Source/platform/image-decoders/jpeg/JPEGImageDecoder.h
index dd2c690cc513aecad60f42b92901c39f9e5f9fb3..9556762080d18c99288aac029df65705477453c4 100644
--- a/third_party/WebKit/Source/platform/image-decoders/jpeg/JPEGImageDecoder.h
+++ b/third_party/WebKit/Source/platform/image-decoders/jpeg/JPEGImageDecoder.h
@@ -54,6 +54,11 @@ public:
     bool decodeToYUV() override;
     void setImagePlanes(PassOwnPtr<ImagePlanes>) override;
     bool hasImagePlanes() const { return m_imagePlanes; }
+    void getAvailableDecodeAndScale(ImageFrame::ColorType* outType, float* scale, float* lowerScale) override;
+    bool activateDecodeAndScale(ImageFrame::ColorType outColor, size_t maxDecodedBytes = noDecodedImageByteLimit) override;
+    void disableDecodeAndScale() override;
+    bool decodeToRGB565Enabled() const { return (m_decodeColor == ImageFrame::RGB565); }
+    bool hasFramebufferChanged() const;
 
     bool outputScanlines();
     unsigned desiredScaleNumerator() const;
@@ -77,6 +82,9 @@ private:
     OwnPtr<ImagePlanes> m_imagePlanes;
     IntSize m_decodedSize;
     bool m_hasColorProfile;
+    ImageFrame::ColorType m_decodeColor;
+    // keep the value to restore after disableDecodeAndScale()
+    size_t m_originalMaxDecodedBytes;
 };
 
 } // namespace blink