Index: third_party/WebKit/Source/platform/image-decoders/ImageDecoder.cpp |
diff --git a/third_party/WebKit/Source/platform/image-decoders/ImageDecoder.cpp b/third_party/WebKit/Source/platform/image-decoders/ImageDecoder.cpp |
index 0b76d3326f24edabb38900dfff72e8440d417c42..0727fe11a8aa0effefe92d11476f747d5a200859 100644 |
--- a/third_party/WebKit/Source/platform/image-decoders/ImageDecoder.cpp |
+++ b/third_party/WebKit/Source/platform/image-decoders/ImageDecoder.cpp |
@@ -265,57 +265,6 @@ bool ImageDecoder::PostDecodeProcessing(size_t index) { |
return true; |
} |
-void ImageDecoder::CorrectAlphaWhenFrameBufferSawNoAlpha(size_t index) { |
- DCHECK(index < frame_buffer_cache_.size()); |
- ImageFrame& buffer = frame_buffer_cache_[index]; |
- |
- // When this frame spans the entire image rect we can SetHasAlpha to false, |
- // since there are logically no transparent pixels outside of the frame rect. |
- if (buffer.OriginalFrameRect().Contains(IntRect(IntPoint(), Size()))) { |
- buffer.SetHasAlpha(false); |
- buffer.SetRequiredPreviousFrameIndex(kNotFound); |
- } else if (buffer.RequiredPreviousFrameIndex() != kNotFound) { |
- // When the frame rect does not span the entire image rect, and it does |
- // *not* have a required previous frame, the pixels outside of the frame |
- // rect will be fully transparent, so we shoudn't SetHasAlpha to false. |
- // |
- // It is a tricky case when the frame does have a required previous frame. |
- // The frame does not have alpha only if everywhere outside its rect |
- // doesn't have alpha. To know whether this is true, we check the start |
- // state of the frame -- if it doesn't have alpha, we're safe. |
- // |
- // We first check that the required previous frame does not have |
- // DisposeOverWritePrevious as its disposal method - this should never |
- // happen, since the required frame should in that case be the required |
- // frame of this frame's required frame. |
- // |
- // If |prev_buffer| is DisposeNotSpecified or DisposeKeep, |buffer| has no |
- // alpha if |prev_buffer| had no alpha. Since InitFrameBuffer() already |
- // copied the alpha state, there's nothing to do here. |
- // |
- // The only remaining case is a DisposeOverwriteBgcolor frame. If |
- // it had no alpha, and its rect is contained in the current frame's |
- // rect, we know the current frame has no alpha. |
- // |
- // For DisposeNotSpecified, DisposeKeep and DisposeOverwriteBgcolor there |
- // is one situation that is not taken into account - when |prev_buffer| |
- // *does* have alpha, but only in the frame rect of |buffer|, we can still |
- // say that this frame has no alpha. However, to determine this, we |
- // potentially need to analyze all image pixels of |prev_buffer|, which is |
- // too computationally expensive. |
- const ImageFrame* prev_buffer = |
- &frame_buffer_cache_[buffer.RequiredPreviousFrameIndex()]; |
- DCHECK(prev_buffer->GetDisposalMethod() != |
- ImageFrame::kDisposeOverwritePrevious); |
- |
- if ((prev_buffer->GetDisposalMethod() == |
- ImageFrame::kDisposeOverwriteBgcolor) && |
- !prev_buffer->HasAlpha() && |
- buffer.OriginalFrameRect().Contains(prev_buffer->OriginalFrameRect())) |
- buffer.SetHasAlpha(false); |
- } |
-} |
- |
bool ImageDecoder::InitFrameBuffer(size_t frame_index) { |
DCHECK(frame_index < frame_buffer_cache_.size()); |