Remove full-size bitmap copy on SkImage::scalePixels->IFG::decodeAndScale

third_party/WebKit/Source/platform/graphics/ImageFrameGenerator.h

 /*
  * Copyright (C) 2012 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 55 matching lines @@
   static PassRefPtr<ImageFrameGenerator> create(
       const SkISize& fullSize,
       bool isMultiFrame,
       const ColorBehavior& colorBehavior) {
     return adoptRef(
         new ImageFrameGenerator(fullSize, isMultiFrame, colorBehavior));
   }
 
   ~ImageFrameGenerator();
 
-  // Decodes and scales the specified frame at |index|. The dimensions and
-  // output format are given in SkImageInfo. Decoded pixels are written into
+  // Decodes and scales the specified frame at |index|.  The dimensions and
+  // output format are given in SkImageInfo.  Decoded pixels are scaled if
+  // necessary, applying the specified filter-quality, and then written into
   // |pixels| with a stride of |rowBytes|. Returns true if decoding was
   // successful.
   bool decodeAndScale(SegmentReader*,
                       bool allDataReceived,
                       size_t index,
                       const SkImageInfo&,
                       void* pixels,
-                      size_t rowBytes);
+                      size_t rowBytes,
+                      SkFilterQuality = kLow_SkFilterQuality);
 
   // Decodes YUV components directly into the provided memory planes. Must not
   // be called unless getYUVComponentSizes has been called and returned true.
   // YUV decoding does not currently support progressive decoding. In order to
   // support it, ImageDecoder needs something analagous to its ImageFrame cache
   // to hold partial planes, and the GPU code needs to handle them.
   bool decodeToYUV(SegmentReader*,
                    size_t index,
                    const SkISize componentSizes[3],
                    void* planes[3],
@@ skipping 55 matching lines @@
   // Prevents multiple decode operations on the same data.
   Mutex m_decodeMutex;
 
   // Protect concurrent access to m_hasAlpha.
   Mutex m_alphaMutex;
 };
 
 }  // namespace blink
 
 #endif