Add animation support for WebP images

Source/core/platform/image-decoders/ImageDecoder.h

 /*
  * Copyright (C) 2006 Apple Computer, Inc.  All rights reserved.
  * Copyright (C) 2008-2009 Torch Mobile, Inc.
  * Copyright (C) Research In Motion Limited 2009-2010. All rights reserved.
  * Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies)
  *
  * 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
@@ skipping 177 matching lines @@
         }
 
         int height() const
         {
             return m_bitmap->bitmap().height();
         }
 
         RefPtr<NativeImageSkia> m_bitmap;
         SkBitmap::Allocator* m_allocator;
         bool m_hasAlpha;
-        IntRect m_originalFrameRect; // This will always just be the entire
-                                     // buffer except for GIF frames whose
-                                     // original rect was smaller than the
-                                     // overall image size.
+        // This will always just be the entire buffer except for GIF or WebP
+        // frames whose original rect was smaller than the overall image size.
+        IntRect m_originalFrameRect;
         FrameStatus m_status;
         unsigned m_duration;
         FrameDisposalMethod m_disposalMethod;
         bool m_premultiplyAlpha;
     };
 
     // ImageDecoder is a base for all format-specific decoders
     // (e.g. JPEGImageDecoder).  This base manages the ImageFrame cache.
     //
     // ENABLE(IMAGE_DECODER_DOWN_SAMPLING) allows image decoders to downsample
@@ skipping 40 matching lines @@
 
         virtual IntSize size() const { return m_size; }
 
         IntSize scaledSize() const
         {
             return m_scaled ? IntSize(m_scaledColumns.size(), m_scaledRows.size()) : size();
         }
 
         // This will only differ from size() for ICO (where each frame is a
         // different icon) or other formats where different frames are different
-        // sizes.  This does NOT differ from size() for GIF, since decoding GIFs
-        // composites any smaller frames against previous frames to create full-
-        // size frames.
+        // sizes. This does NOT differ from size() for GIF or WebP, since
+        // decoding GIF or WebP composites any smaller frames against previous
+        // frames to create full-size frames.
         virtual IntSize frameSizeAtIndex(size_t) const
         {
             return size();
         }
 
         // Returns whether the size is legal (i.e. not going to result in
         // overflow elsewhere).  If not, marks decoding as failed.
         virtual bool setSize(unsigned width, unsigned height)
         {
             if (isOverSize(width, height))
@@ skipping 85 matching lines @@
         // clean up any local data.
         virtual bool setFailed()
         {
             m_failed = true;
             return false;
         }
 
         bool failed() const { return m_failed; }
 
         // Clears decoded pixel data from before the provided frame unless that
-        // data may be needed to decode future frames (e.g. due to GIF frame
-        // compositing).
+        // data may be needed to decode future frames (e.g. due to GIF/WebP
+        // frame compositing).
         virtual void clearFrameBufferCache(size_t) { }
 
 #if ENABLE(IMAGE_DECODER_DOWN_SAMPLING)
         void setMaxNumPixels(int m) { m_maxNumPixels = m; }
 #endif
 
         // If the image has a cursor hot-spot, stores it in the argument
         // and returns true. Otherwise returns false.
         virtual bool hotSpot(IntPoint&) const { return false; }
 
@@ skipping 39 matching lines @@
         IntSize m_size;
         bool m_sizeAvailable;
         int m_maxNumPixels;
         bool m_isAllDataReceived;
         bool m_failed;
     };
 
 } // namespace WebCore
 
 #endif