Reland: Don't early out recursion into PaintLayerChildren when computing composited bounds.

third_party/WebKit/Source/core/layout/ClipRect.h

 /*
  * Copyright (C) 2003, 2009, 2012 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 59 matching lines @@
   bool isEmpty() const { return m_rect.isEmpty(); }
   bool intersects(const HitTestLocation&) const;
 
   // These have no semantic use. They are used for use-counting.
   bool isClippedByClipCss() const { return m_isClippedByClipCss; }
   ClipRect& setIsClippedByClipCss() {
     m_isClippedByClipCss = true;
     return *this;
   }
 
-  String toString() { return m_rect.toString(); }
+  String toString() const { return m_rect.toString(); }
 
  private:
   LayoutRect m_rect;
   bool m_hasRadius;
   bool m_isClippedByClipCss;
 };
 
 inline ClipRect intersection(const ClipRect& a, const ClipRect& b) {
   ClipRect c = a;
   c.intersect(b);
   return c;
 }
 
 }  // namespace blink
 
 #endif  // ClipRect_h