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 457666d25dbf9719bca561b730007b49d180edd0..e9d3fb1f878bb29f75fece6510d53e420672b566 100644
--- a/third_party/WebKit/Source/platform/image-decoders/gif/GIFImageDecoder.cpp
+++ b/third_party/WebKit/Source/platform/image-decoders/gif/GIFImageDecoder.cpp
@@ -83,9 +83,11 @@ 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();
+    ASSERT(haveUpdatedFrameCount());
+    return (m_reader && (index < m_reader->imagesCount()) && m_reader->frameContext(index)->isComplete())
+        || ImageDecoder::frameIsFullyReceivedAtIndex(index);
 }
 
 float GIFImageDecoder::frameDurationAtIndex(size_t index) const
@@ -296,8 +298,7 @@ void GIFImageDecoder::initializeNewFrame(size_t index)
 
 void GIFImageDecoder::decode(size_t index)
 {
-    parse(GIFFrameCountQuery);
-
+    ASSERT(haveUpdatedFrameCount());
     if (failed())
         return;