Have Node::ensureRareData() return a reference

Source/core/dom/Node.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * 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
@@ skipping 779 matching lines @@
         InspectorCounters::incrementCounter(InspectorCounters::NodeCounter);
     }
 
     virtual void didMoveToNewDocument(Document& oldDocument);
 
     virtual void addSubresourceAttributeURLs(ListHashSet<KURL>&) const { }
 
     bool hasRareData() const { return getFlag(HasRareDataFlag); }
 
     NodeRareData* rareData() const;
-    NodeRareData* ensureRareData();
+    NodeRareData& ensureRareData();
     void clearRareData();
 
     void clearEventTargetData();
 
     void setHasCustomStyleCallbacks() { setFlag(true, HasCustomStyleCallbacksFlag); }
 
     Document* documentInternal() const { return treeScope().documentScope(); }
     void setTreeScope(TreeScope* scope) { m_treeScope = scope; }
 
 private:
@@ skipping 125 matching lines @@
 
 } // namespace WebCore
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showTree(const WebCore::Node*);
 void showNodePath(const WebCore::Node*);
 #endif
 
 #endif