Add display list fallback reason histograms for 2D canvas

third_party/WebKit/Source/core/html/HTMLImageElement.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2008, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 80 matching lines @@
 
     const AtomicString imageSourceURL() const override;
 
     HTMLFormElement* formOwner() const override;
     void formRemovedFromTree(const Node& formRoot);
     virtual void ensureFallbackContent();
     virtual void ensureFallbackForGeneratedContent();
     virtual void ensurePrimaryContent();
 
     // CanvasImageSource implementation
-    PassRefPtr<Image> getSourceImageForCanvas(SourceImageStatus*, AccelerationHint) const override;
+    PassRefPtr<Image> getSourceImageForCanvas(SourceImageStatus*, AccelerationHint, SnapshotReason) const override;
     bool isSVGSource() const override;
     bool wouldTaintOrigin(SecurityOrigin*) const override;
     FloatSize elementSize() const override;
     FloatSize defaultDestinationSize() const override;
     const KURL& sourceURL() const override;
     bool isOpaque() const override;
 
     // public so that HTMLPictureElement can call this as well.
     void selectSourceURL(ImageLoader::UpdateFromElementBehavior);
     void reattachFallbackContent();
@@ skipping 61 matching lines @@
     unsigned m_intrinsicSizingViewportDependant : 1;
     unsigned m_useFallbackContent : 1;
     unsigned m_isFallbackImage : 1;
 
     ReferrerPolicy m_referrerPolicy;
 };
 
 } // namespace blink
 
 #endif // HTMLImageElement_h