Do-not-commit: Count layout tree memory usage

third_party/WebKit/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 32 matching lines @@
 
   PaintInvalidationReason invalidatePaintIfNeeded(
       const PaintInvalidatorContext&) const final;
 
   void canvasSizeChanged();
 
   void styleDidChange(StyleDifference, const ComputedStyle* oldStyle) override;
 
   const char* name() const override { return "LayoutHTMLCanvas"; }
 
+  char objectSize() const override { return sizeof(this); }
+
  private:
   void paintReplaced(const PaintInfo&, const LayoutPoint&) const override;
   void intrinsicSizeChanged() override { canvasSizeChanged(); }
 
   CompositingReasons additionalCompositingReasons() const override;
 };
 
 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutHTMLCanvas, isCanvas());
 
 }  // namespace blink
 
 #endif  // LayoutHTMLCanvas_h