Index: third_party/WebKit/Source/platform/image-decoders/webp/WEBPImageDecoder.cpp |
diff --git a/third_party/WebKit/Source/platform/image-decoders/webp/WEBPImageDecoder.cpp b/third_party/WebKit/Source/platform/image-decoders/webp/WEBPImageDecoder.cpp |
index 1e55c716838dfe0a1dfd4ad611bfa2dad053086c..38045ba73c1c17799c01e3044e5ea702cd666367 100644 |
--- a/third_party/WebKit/Source/platform/image-decoders/webp/WEBPImageDecoder.cpp |
+++ b/third_party/WebKit/Source/platform/image-decoders/webp/WEBPImageDecoder.cpp |
@@ -252,11 +252,14 @@ bool WEBPImageDecoder::initFrameBuffer(size_t frameIndex) |
return setFailed(); |
m_frameBackgroundHasAlpha = !buffer.originalFrameRect().contains(IntRect(IntPoint(), size())); |
} else { |
- const ImageFrame& prevBuffer = m_frameBufferCache[requiredPreviousFrameIndex]; |
+ ImageFrame& prevBuffer = m_frameBufferCache[requiredPreviousFrameIndex]; |
ASSERT(prevBuffer.getStatus() == ImageFrame::FrameComplete); |
- // Preserve the last frame as the starting state for this frame. |
- if (!buffer.copyBitmapData(prevBuffer)) |
+ // Preserve the last frame as the starting state for this frame. We try |
+ // to reuse |prevBuffer| as starting state to avoid copying. |
+ // For BlendAtopPreviousFrame, both frames are required, so we can't |
+ // take over its image data using takeBitmapDataIfWritable. |
+ if ((buffer.getAlphaBlendSource() == ImageFrame::BlendAtopPreviousFrame || !buffer.takeBitmapDataIfWritable(&prevBuffer)) && !buffer.copyBitmapData(prevBuffer)) |
return setFailed(); |
if (prevBuffer.getDisposalMethod() == ImageFrame::DisposeOverwriteBgcolor) { |