Add support for Animated PNG

third_party/WebKit/Source/platform/image-decoders/gif/GIFImageDecoder.cpp

Index: third_party/WebKit/Source/platform/image-decoders/gif/GIFImageDecoder.cpp
diff --git a/third_party/WebKit/Source/platform/image-decoders/gif/GIFImageDecoder.cpp b/third_party/WebKit/Source/platform/image-decoders/gif/GIFImageDecoder.cpp
index 357917f67d3cff36f6b0a9e23a76c2d9e9ad86c2..307e6a4f93d4c67f6793c152bb4172390813ec37 100644
--- a/third_party/WebKit/Source/platform/image-decoders/gif/GIFImageDecoder.cpp
+++ b/third_party/WebKit/Source/platform/image-decoders/gif/GIFImageDecoder.cpp
@@ -189,12 +189,13 @@ bool GIFImageDecoder::frameComplete(size_t frameIndex) {
   // Initialize the frame if necessary.  Some GIFs insert do-nothing frames,
   // in which case we never reach haveDecodedRow() before getting here.
   if (!initFrameBuffer(frameIndex))
-    return false;  // initFrameBuffer() has already called setFailed().
+    return setFailed();
 
-  m_frameBufferCache[frameIndex].setStatus(ImageFrame::FrameComplete);
   if (!m_currentBufferSawAlpha)
     correctAlphaWhenFrameBufferSawNoAlpha(frameIndex);
 
+  m_frameBufferCache[frameIndex].setStatus(ImageFrame::FrameComplete);
+
   return true;
 }