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

Source/web/WebNode.cpp

 /*
  * Copyright (C) 2009 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 89 matching lines @@
 }
 
 bool WebNode::setNodeValue(const WebString& value)
 {
     m_private->setNodeValue(value);
     return true;
 }
 
 WebDocument WebNode::document() const
 {
-    return WebDocument(m_private->document());
+    return WebDocument(&m_private->document());
 }
 
 WebNode WebNode::firstChild() const
 {
     return WebNode(m_private->firstChild());
 }
 
 WebNode WebNode::lastChild() const
 {
     return WebNode(m_private->lastChild());
@@ skipping 31 matching lines @@
 
 bool WebNode::isTextNode() const
 {
     return m_private->isTextNode();
 }
 
 bool WebNode::isFocusable() const
 {
     if (!m_private->isElementNode())
         return false;
-    m_private->document()->updateLayoutIgnorePendingStylesheets();
+    m_private->document().updateLayoutIgnorePendingStylesheets();
     return toElement(m_private.get())->isFocusable();
 }
 
 bool WebNode::isContentEditable() const
 {
     return m_private->isContentEditable();
 }
 
 bool WebNode::isElementNode() const
 {
@@ skipping 49 matching lines @@
 
 bool WebNode::remove()
 {
     TrackExceptionState es;
     m_private->remove(es);
     return !es.hadException();
 }
 
 bool WebNode::hasNonEmptyBoundingBox() const
 {
-    m_private->document()->updateLayoutIgnorePendingStylesheets();
+    m_private->document().updateLayoutIgnorePendingStylesheets();
     return m_private->hasNonEmptyBoundingBox();
 }
 
 WebPluginContainer* WebNode::pluginContainer() const
 {
     if (isNull())
         return 0;
     const Node* coreNode = constUnwrap<Node>();
     if (coreNode->hasTagName(HTMLNames::objectTag) || coreNode->hasTagName(HTMLNames::embedTag)) {
         RenderObject* object = coreNode->renderer();
@@ skipping 24 matching lines @@
     m_private = node;
     return *this;
 }
 
 WebNode::operator PassRefPtr<Node>() const
 {
     return m_private.get();
 }
 
 } // namespace WebKit