DeferredImageDecoder: early-out onGetYUV8Planes when possible

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 28 matching lines @@
 
 class ImageFrameGenerator;
 
 // Implements SkImageGenerator, used by SkPixelRef to populate a discardable memory
 // with a decoded image frame. ImageFrameGenerator does the actual decoding.
 //
 class PLATFORM_EXPORT DecodingImageGenerator final : public SkImageGenerator {
     USING_FAST_MALLOC(DecodingImageGenerator);
     WTF_MAKE_NONCOPYABLE(DecodingImageGenerator);
 public:
-    static SkImageGenerator* create(SkData*);
-
     DecodingImageGenerator(PassRefPtr<ImageFrameGenerator>, const SkImageInfo&, size_t index);
     ~DecodingImageGenerator() override;
 
     void setGenerationId(size_t id) { m_generationId = id; }
+    void setCanYUVDecode(bool yes) { m_canYUVDecode = yes; }
+
+    static SkImageGenerator* create(SkData*); // Highly unsual access.
 
 protected:
     SkData* onRefEncodedData() override;
 
     bool onGetPixels(const SkImageInfo&, void* pixels, size_t rowBytes, SkPMColor table[], int* tableCount) override;
 
     bool onGetYUV8Planes(SkISize sizes[3], void* planes[3], size_t rowBytes[3], SkYUVColorSpace*) override;
 
 private:
     RefPtr<ImageFrameGenerator> m_frameGenerator;
     size_t m_frameIndex;
     size_t m_generationId;
+    bool m_canYUVDecode;
 };
 
 } // namespace blink
 
 #endif // DecodingImageGenerator_h_