Large canvas does not honor containing div's border radius

Source/core/platform/graphics/GraphicsContextAnnotation.cpp

 /*
  * Copyright (C) 2013 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 53 matching lines @@
     case WebCore::PaintPhaseSelfOutline:
         return "SelfOutline";
     case WebCore::PaintPhaseSelection:
         return "Selection";
     case WebCore::PaintPhaseCollapsedTableBorders:
         return "CollapsedTableBorders";
     case WebCore::PaintPhaseTextClip:
         return "TextClip";
     case WebCore::PaintPhaseMask:
         return "Mask";
+    case WebCore::PaintPhaseBorderRadiusMask:
+        return "BorderRadiusMask";
     default:
         ASSERT_NOT_REACHED();
         return "<unknown>";
     }
 }
 
 }
 
 namespace WebCore {
 
@@ skipping 65 matching lines @@
     m_context->beginAnnotation(GraphicsContextAnnotation(paintInfo, object));
 }
 
 void GraphicsContextAnnotator::finishAnnotation()
 {
     ASSERT(m_context);
     m_context->endAnnotation();
 }
 
 }