Add support for Animated PNG

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 240 matching lines @@
   //        so this method can be made non-virtual. It is used in the test
   //        ImageFrameGeneratorTest::clearMultiFrameDecode. The test needs to
   //        be modified since two frames may be kept in cache, instead of
   //        always just one, with this clearCacheExceptFrame implementation.
   virtual size_t clearCacheExceptFrame(size_t);
 
   // 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; }
 
-  virtual void setMemoryAllocator(SkBitmap::Allocator* allocator) {
+  void setMemoryAllocator(SkBitmap::Allocator* allocator) {
     // FIXME: this doesn't work for images with multiple frames.
     if (m_frameBufferCache.isEmpty()) {
-      m_frameBufferCache.resize(1);
-      m_frameBufferCache[0].setRequiredPreviousFrameIndex(
-          findRequiredPreviousFrame(0, false));
+      // Ensure that initializeNewFrame is called, after parsing if
+      // necessary.
+      if (!frameCount())
+        return;
     }
+
     m_frameBufferCache[0].setMemoryAllocator(allocator);
   }
 
   virtual bool canDecodeToYUV() { return false; }
   virtual bool decodeToYUV() { return false; }
   virtual void setImagePlanes(std::unique_ptr<ImagePlanes>) {}
 
  protected:
   ImageDecoder(AlphaOption alphaOption,
                const ColorBehavior& colorBehavior,
@@ skipping 28 matching lines @@
   virtual void clearFrameBuffer(size_t frameIndex);
 
   // Decodes the image sufficiently to determine the image size.
   virtual void decodeSize() = 0;
 
   // Decodes the image sufficiently to determine the number of frames and
   // returns that number.
   virtual size_t decodeFrameCount() { return 1; }
 
   // Called to initialize the frame buffer with the given index, based on the
-  // provided and previous frame's characteristics. Returns true on success. On
-  // failure, this will mark the image as failed. Before calling this method,
-  // the caller must verify that the frame exists.
+  // provided and previous frame's characteristics. Returns true on success.
+  // Before calling this method, the caller must verify that the frame exists.
+  // On failure, the client should call setFailed. This method does not call
+  // setFailed itself because that might delete the object directly making this
+  // call.
   bool initFrameBuffer(size_t);
 
   // Performs any additional setup of the requested frame after it has been
   // initially created, e.g. setting a duration or disposal method.
   virtual void initializeNewFrame(size_t) {}
 
   // Decodes the requested frame.
   virtual void decode(size_t) = 0;
 
   // This method is only required for animated images. It returns a vector with
@@ skipping 90 matching lines @@
   bool m_hasHistogrammedColorSpace = false;
 
   sk_sp<SkColorSpace> m_embeddedColorSpace = nullptr;
   bool m_sourceToTargetColorTransformNeedsUpdate = false;
   std::unique_ptr<SkColorSpaceXform> m_sourceToTargetColorTransform;
 };
 
 }  // namespace blink
 
 #endif