JPEGImageDecoder RGB565 and downsample support and related Skia imagegenerator changes

third_party/WebKit/Source/platform/image-decoders/ImageDecoder.h

 /*
  * Copyright (C) 2006 Apple Computer, Inc.  All rights reserved.
  * Copyright (C) Research In Motion Limited 2009-2010. 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 275 matching lines @@
             m_frameBufferCache[0].setRequiredPreviousFrameIndex(
                 findRequiredPreviousFrame(0, false));
         }
         m_frameBufferCache[0].setMemoryAllocator(allocator);
     }
 
     virtual bool canDecodeToYUV() { return false; }
     virtual bool decodeToYUV() { return false; }
     virtual void setImagePlanes(PassOwnPtr<ImagePlanes>) { }
 
+    virtual void getAvailableDecodeAndScale(ImageFrame::ColorType* outType, float* scale, float* lowerScale)
+    {
+        defaultDecodeAndScale(outType, scale, lowerScale);
+    }
+    virtual bool activateDecodeAndScale(ImageFrame::ColorType outColor, size_t maxDecodedBytes = noDecodedImageByteLimit) { return false; }
+    virtual void disableDecodeAndScale() { }
+    static void defaultDecodeAndScale(ImageFrame::ColorType* outType, float* scale, float* lowerScale);
+
 protected:
     // Calculates the most recent frame whose image data may be needed in
     // order to decode frame |frameIndex|, based on frame disposal methods
     // and |frameRectIsOpaque|, where |frameRectIsOpaque| signifies whether
     // the rectangle of frame at |frameIndex| is known to be opaque.
     // If no previous frame's data is required, returns WTF::kNotFound.
     //
     // This function requires that the previous frame's
     // |m_requiredPreviousFrameIndex| member has been set correctly. The
     // easiest way to ensure this is for subclasses to call this method and
@@ skipping 48 matching lines @@
 
     IntSize m_size;
     bool m_sizeAvailable;
     bool m_isAllDataReceived;
     bool m_failed;
 };
 
 } // namespace blink
 
 #endif