Have Node::document() return a reference instead of a pointer

Source/core/svg/SVGCursorElement.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007 Rob Buis <buis@kde.org>
  *
  * 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.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 120 matching lines @@
     HashSet<SVGElement*>::const_iterator end = m_clients.end();
 
     for (; it != end; ++it)
         (*it)->setNeedsStyleRecalc();
 }
 
 void SVGCursorElement::addSubresourceAttributeURLs(ListHashSet<KURL>& urls) const
 {
     SVGElement::addSubresourceAttributeURLs(urls);
 
-    addSubresourceURL(urls, document()->completeURL(hrefCurrentValue()));
+    addSubresourceURL(urls, document().completeURL(hrefCurrentValue()));
 }
 
 }