Early reporting of opaqueness by decoders.

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

 /*
  * Copyright (C) 2006 Apple Computer, 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 27 matching lines @@
     JPEGImageDecoder(AlphaOption, GammaAndColorProfileOption, size_t maxDecodedBytes);
     ~JPEGImageDecoder() override;
 
     // ImageDecoder:
     String filenameExtension() const override { return "jpg"; }
     void onSetData(SharedBuffer* data) override;
     IntSize decodedSize() const override { return m_decodedSize; }
     bool setSize(unsigned width, unsigned height) override;
     IntSize decodedYUVSize(int component) const override;
     size_t decodedYUVWidthBytes(int component) const override;
+    bool frameHasAlphaAtIndex(size_t index) const override;
     bool canDecodeToYUV() override;
     bool decodeToYUV() override;
     void setImagePlanes(PassOwnPtr<ImagePlanes>) override;
     bool hasImagePlanes() const { return m_imagePlanes; }
 
     bool outputScanlines();
     unsigned desiredScaleNumerator() const;
     void complete();
 
     void setOrientation(ImageOrientation orientation) { m_orientation = orientation; }
@@ skipping 10 matching lines @@
     void decode(bool onlySize);
 
     OwnPtr<JPEGImageReader> m_reader;
     OwnPtr<ImagePlanes> m_imagePlanes;
     IntSize m_decodedSize;
 };
 
 } // namespace blink
 
 #endif