GIF decoding to Index8, unit tests and misusing unit test as benchmark

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 2ebd7797caf99844abc34018d95e42f885f8b453..1963be5fda0572f12b8efd7b37325b7c44bfdcef 100644
--- a/third_party/WebKit/Source/platform/image-decoders/ImageDecoder.h
+++ b/third_party/WebKit/Source/platform/image-decoders/ImageDecoder.h
@@ -297,6 +297,10 @@ public:
     virtual bool canDecodeToYUV() { return false; }
     virtual bool decodeToYUV() { return false; }
     virtual void setImagePlanes(PassOwnPtr<ImagePlanes>) { }
+    virtual bool canDecodeTo(size_t index, ImageFrame::ColorType outputType)
+    {
+        return outputType == ImageFrame::N32;
+    }
 
 protected:
     // Calculates the most recent frame whose image data may be needed in