[S.P.] Don't draw frames of animated images that are offscreen

Source/core/layout/LayoutHTMLCanvas.h

 /*
  * Copyright (C) 2004, 2006, 2007, 2009 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 20 matching lines @@
 namespace blink {
 
 class HTMLCanvasElement;
 
 class LayoutHTMLCanvas final : public LayoutReplaced {
 public:
     explicit LayoutHTMLCanvas(HTMLCanvasElement*);
 
     virtual bool isOfType(LayoutObjectType type) const override { return type == LayoutObjectCanvas || LayoutReplaced::isOfType(type); }
     virtual DeprecatedPaintLayerType layerTypeRequired() const override;
-    virtual PaintInvalidationReason invalidatePaintIfNeeded(const PaintInvalidationState&, const LayoutBoxModelObject&) override final;
+    virtual PaintInvalidationReason invalidatePaintIfNeeded(PaintInvalidationState&, const LayoutBoxModelObject&) override final;
 
     void canvasSizeChanged();
 
     virtual const char* name() const override { return "LayoutHTMLCanvas"; }
 
 private:
     virtual void paintReplaced(const PaintInfo&, const LayoutPoint&) override;
     virtual void intrinsicSizeChanged() override { canvasSizeChanged(); }
 
     virtual CompositingReasons additionalCompositingReasons() const override;
 };
 
 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutHTMLCanvas, isCanvas());
 
 } // namespace blink
 
 #endif // LayoutHTMLCanvas_h