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

Source/core/inspector/InspectorCSSAgent.cpp

 /*
  * Copyright (C) 2010, 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:
  * 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 1213 matching lines @@
     }
     *errorString = InspectorDOMAgent::toErrorString(es);
 }
 
 void InspectorCSSAgent::addRule(ErrorString* errorString, const int contextNodeId, const String& selector, RefPtr<TypeBuilder::CSS::CSSRule>& result)
 {
     Node* node = m_domAgent->assertNode(errorString, contextNodeId);
     if (!node)
         return;
 
-    InspectorStyleSheet* inspectorStyleSheet = viaInspectorStyleSheet(node->document(), true);
+    InspectorStyleSheet* inspectorStyleSheet = viaInspectorStyleSheet(&node->document(), true);
     if (!inspectorStyleSheet) {
         *errorString = "No target stylesheet found";
         return;
     }
 
     TrackExceptionState es;
     OwnPtr<AddRuleAction> action = adoptPtr(new AddRuleAction(inspectorStyleSheet, selector));
     AddRuleAction* rawAction = action.get();
     bool success = m_domAgent->history()->perform(action.release(), es);
     if (!success) {
@@ skipping 532 matching lines @@
             documentsToChange.add(element->ownerDocument());
     }
 
     m_nodeIdToForcedPseudoState.clear();
     for (HashSet<Document*>::iterator it = documentsToChange.begin(), end = documentsToChange.end(); it != end; ++it)
         (*it)->setNeedsStyleRecalc();
 }
 
 } // namespace WebCore