Allowing YUV data to be retrieved from the JPEG Decoder.

Source/platform/image-decoders/ImageDecoder.h

Index: Source/platform/image-decoders/ImageDecoder.h
diff --git a/Source/platform/image-decoders/ImageDecoder.h b/Source/platform/image-decoders/ImageDecoder.h
index 559213011fae93fa14db64b85678ba0c704652f1..5684299a75a5627e2ce634a75771fe7afd43e3ad 100644
--- a/Source/platform/image-decoders/ImageDecoder.h
+++ b/Source/platform/image-decoders/ImageDecoder.h
@@ -49,6 +49,20 @@
 
 namespace blink {
 
+// DecodingBuffers can be used to decode color components into provided buffers instead of using an ImageFrame.
+class DecodingBuffers {
+public:
+    DecodingBuffers();
+
+    void set(void* planes[3], size_t rowBytes[3]);

[Peter Kasting, 2014/07/24 18:08:14]

Nit: Do we really have to use void* for these planes?  Wouldn't char* be a more
appropriate type, since this represents "block of bytes"?

+    void* getPlane(int) const;

[Peter Kasting, 2014/07/24 18:08:14]

Const functions should not return non-const pointers.  Either make the pointer
const, or make the function non-const.

+    size_t getRowBytes(int) const;
+
+private:
+    void* m_planes[3];
+    size_t m_rowBytes[3];
+};
+
 // ImageDecoder is a base for all format-specific decoders
 // (e.g. JPEGImageDecoder). This base manages the ImageFrame cache.
 //
@@ -100,7 +114,7 @@ public:
 
     // Decoders which downsample images should override this method to
     // return the actual decoded size.
-    virtual IntSize decodedSize() const { return size(); }
+    virtual IntSize decodedSize(int component = 0) const { return size(); }
 
     // This will only differ from size() for ICO (where each frame is a
     // different icon) or other formats where different frames are different
@@ -252,6 +266,11 @@ public:
         m_frameBufferCache[0].setMemoryAllocator(allocator);
     }
 
+    virtual void setAcceleratedYUVDecoding(bool) { }
+    virtual bool acceleratedYUVDecoding() const { return false; }
+    virtual bool doAcceleratedYUVDecoding() { return false; }
+    virtual void setDecodingBuffers(OwnPtr<DecodingBuffers>&) { }
+
 protected:
     // Calculates the most recent frame whose image data may be needed in
     // order to decode frame |frameIndex|, based on frame disposal methods