blink: Fix frame completion querying for static images.

third_party/WebKit/Source/platform/image-decoders/ImageDecoder.h

Index: third_party/WebKit/Source/platform/image-decoders/ImageDecoder.h
diff --git a/third_party/WebKit/Source/platform/image-decoders/ImageDecoder.h b/third_party/WebKit/Source/platform/image-decoders/ImageDecoder.h
index a41bf4e6d6b75d7d5ee0f9d2eae1ea468fcc6ec6..17521b18552d7a710976181731418de57fe9e7cc 100644
--- a/third_party/WebKit/Source/platform/image-decoders/ImageDecoder.h
+++ b/third_party/WebKit/Source/platform/image-decoders/ImageDecoder.h
@@ -195,6 +195,9 @@ class PLATFORM_EXPORT ImageDecoder {
   // Whether or not the frame is fully received.
   virtual bool FrameIsCompleteAtIndex(size_t) const;
 
+  // Returns true if a cached complete decode is available.
+  bool FrameIsDecodedAtIndex(size_t) const;
+
   // Duration for displaying a frame in milliseconds. This method is only used
   // by animated images.
   virtual float FrameDurationAtIndex(size_t) const { return 0; }