Fix ImageDecoder::frameIsCompleteAtIndex - fully received instead of decoded.

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 824764c5534764548b2c1eaa4225592de2b26d5f..340e6cae4337514ee30345fa4d401e98cabc9a2a 100644
--- a/third_party/WebKit/Source/platform/image-decoders/gif/GIFImageDecoder.cpp
+++ b/third_party/WebKit/Source/platform/image-decoders/gif/GIFImageDecoder.cpp
@@ -83,7 +83,7 @@ int GIFImageDecoder::repetitionCount() const
     return m_repetitionCount;
 }
 
-bool GIFImageDecoder::frameIsCompleteAtIndex(size_t index) const
+bool GIFImageDecoder::frameIsFullyReceivedAtIndex(size_t index) const
 {
     return m_reader && (index < m_reader->imagesCount()) && m_reader->frameContext(index)->isComplete();

[Peter Kasting, 2016/05/10 00:00:13]

Hmm.  This will always return false if decoding fails (i.e. if setFailed()
returns true).  Maybe it should always return true in that case instead?

[aleksandar.stojiljkovic, 2016/05/10 21:59:31]

What would be the usage of returning "frame is fully received" in case of
failure? 

[Peter Kasting, 2016/05/11 00:33:02]

We know we're not going to do any further updating/decoding, so anyone wanting
to know "is the image finalizable" should probably get back "yes".

[aleksandar.stojiljkovic, 2016/05/11 11:05:15]

The usage of this is in [1] - GraphicsContext::computeFilterQuality.
If image is not fully received, then lower quality interpolation is used. So for
case of failure we don't use high quality sampling. I think it is better to
leave it as it was.

[1]
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit...

[scroggo_chromium, 2016/05/11 15:17:34]

But it also will be used in crrev.com/1925533003 to state that we should use the
same genID so we'll use the same image from the cache, right?

[Peter Kasting, 2016/05/11 18:29:34]

The only reason we ever use low-quality filtering is so we don't spend too much
time filtering an image which is going to be erased momentarily and redrawn in a
different state.  Once failure occurs the image is finalized, we don't redraw
it, and thus we should use high-quality filtering, even on failed images.

[aleksandar.stojiljkovic, 2016/05/16 13:09:49]

Done.
Clear now; failed() added to "fully received" computation.

 }