Large canvas does not honor containing div's border radius

Source/core/rendering/RenderBox.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2006, 2007 Apple 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 473 matching lines @@
     virtual LayoutRect overflowClipRect(const LayoutPoint& location, RenderRegion*, OverlayScrollbarSizeRelevancy = IgnoreOverlayScrollbarSize);
     LayoutRect clipRect(const LayoutPoint& location, RenderRegion*);
     virtual bool hasControlClip() const { return false; }
     virtual LayoutRect controlClipRect(const LayoutPoint&) const { return LayoutRect(); }
     bool pushContentsClip(PaintInfo&, const LayoutPoint& accumulatedOffset, ContentsClipBehavior);
     void popContentsClip(PaintInfo&, PaintPhase originalPhase, const LayoutPoint& accumulatedOffset);
 
     virtual void paintObject(PaintInfo&, const LayoutPoint&) { ASSERT_NOT_REACHED(); }
     virtual void paintBoxDecorations(PaintInfo&, const LayoutPoint&);
     virtual void paintMask(PaintInfo&, const LayoutPoint&);
+    virtual void paintClippingMask(PaintInfo&, const LayoutPoint&);
     virtual void imageChanged(WrappedImagePtr, const IntRect* = 0);
 
     // Called when a positioned object moves but doesn't necessarily change size.  A simplified layout is attempted
     // that just updates the object's position. If the size does change, the object remains dirty.
     bool tryLayoutDoingPositionedMovementOnly()
     {
         LayoutUnit oldWidth = width();
         updateLogicalWidth();
         // If we shrink to fit our width may have changed, so we still need full layout.
         if (oldWidth != width())
@@ skipping 257 matching lines @@
         if (UNLIKELY(m_inlineBoxWrapper != 0))
             deleteLineBoxWrapper();
     }
 
     m_inlineBoxWrapper = boxWrapper;
 }
 
 } // namespace WebCore
 
 #endif // RenderBox_h