High CPU and increased memory usage fix for high-res (GIF, WEBP...) animations.

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 30 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:
+    // Make SkImageGenerator::kNeedNewImageUniqueID accessible.
+    enum {
+        kNeedNewImageUniqueID = SkImageGenerator::kNeedNewImageUniqueID
+    };
+
     static SkImageGenerator* create(SkData*);
 
-    DecodingImageGenerator(PassRefPtr<ImageFrameGenerator>, const SkImageInfo&, PassRefPtr<SegmentReader>, bool allDataReceived, size_t index);
+    DecodingImageGenerator(PassRefPtr<ImageFrameGenerator>, const SkImageInfo&, PassRefPtr<SegmentReader>, bool allDataReceived, size_t index, uint32_t uniqueID = kNeedNewImageUniqueID);
     ~DecodingImageGenerator() override;
 
     void setCanYUVDecode(bool yes) { m_canYUVDecode = yes; }
 
 protected:
     SkData* onRefEncodedData(GrContext* ctx) override;
 
     bool onGetPixels(const SkImageInfo&, void* pixels, size_t rowBytes, SkPMColor table[], int* tableCount) override;
 
     bool onQueryYUV8(SkYUVSizeInfo*, SkYUVColorSpace*) const override;
 
     bool onGetYUV8Planes(const SkYUVSizeInfo&, void* planes[3]) override;
 
 private:
     RefPtr<ImageFrameGenerator> m_frameGenerator;
     const RefPtr<SegmentReader> m_data; // Data source.
     const bool m_allDataReceived;
     const size_t m_frameIndex;
     bool m_canYUVDecode;
 };
 
 } // namespace blink
 
 #endif // DecodingImageGenerator_h_