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

Source/core/html/HTMLScriptElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *
  * 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.
@@ skipping 72 matching lines @@
 void HTMLScriptElement::setText(const String &value)
 {
     RefPtr<Node> protectFromMutationEvents(this);
 
     if (hasOneTextChild()) {
         toText(firstChild())->setData(value);
         return;
     }
 
     removeChildren();
-    appendChild(document()->createTextNode(value.impl()), IGNORE_EXCEPTION);
+    appendChild(document().createTextNode(value.impl()), IGNORE_EXCEPTION);
 }
 
 void HTMLScriptElement::setAsync(bool async)
 {
     setBooleanAttribute(asyncAttr, async);
     m_loader->handleAsyncAttribute();
 }
 
 bool HTMLScriptElement::async() const
 {
     return fastHasAttribute(asyncAttr) || (m_loader->forceAsync());
 }
 
 KURL HTMLScriptElement::src() const
 {
-    return document()->completeURL(sourceAttributeValue());
+    return document().completeURL(sourceAttributeValue());
 }
 
 void HTMLScriptElement::addSubresourceAttributeURLs(ListHashSet<KURL>& urls) const
 {
     HTMLElement::addSubresourceAttributeURLs(urls);
 
     addSubresourceURL(urls, src());
 }
 
 String HTMLScriptElement::sourceAttributeValue() const
@@ skipping 42 matching lines @@
 }
 
 void HTMLScriptElement::dispatchLoadEvent()
 {
     ASSERT(!m_loader->haveFiredLoadEvent());
     dispatchEvent(Event::create(eventNames().loadEvent));
 }
 
 PassRefPtr<Element> HTMLScriptElement::cloneElementWithoutAttributesAndChildren()
 {
-    return adoptRef(new HTMLScriptElement(tagQName(), document(), false, m_loader->alreadyStarted()));
+    return adoptRef(new HTMLScriptElement(tagQName(), &document(), false, m_loader->alreadyStarted()));
 }
 
 }