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

Source/core/css/CSSStyleSheet.cpp

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2006, 2007, 2012 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.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 62 matching lines @@
     return adoptRef(new CSSStyleSheet(sheet, ownerRule));
 }
 
 PassRefPtr<CSSStyleSheet> CSSStyleSheet::create(PassRefPtr<StyleSheetContents> sheet, Node* ownerNode)
 {
     return adoptRef(new CSSStyleSheet(sheet, ownerNode, false, TextPosition::minimumPosition()));
 }
 
 PassRefPtr<CSSStyleSheet> CSSStyleSheet::createInline(Node* ownerNode, const KURL& baseURL, const TextPosition& startPosition, const String& encoding)
 {
-    CSSParserContext parserContext(ownerNode->document(), baseURL, encoding);
+    CSSParserContext parserContext(&ownerNode->document(), baseURL, encoding);
     RefPtr<StyleSheetContents> sheet = StyleSheetContents::create(baseURL.string(), parserContext);
     return adoptRef(new CSSStyleSheet(sheet.release(), ownerNode, true, startPosition));
 }
 
 CSSStyleSheet::CSSStyleSheet(PassRefPtr<StyleSheetContents> contents, CSSImportRule* ownerRule)
     : m_contents(contents)
     , m_isInlineStylesheet(false)
     , m_isDisabled(false)
     , m_ownerNode(0)
     , m_ownerRule(ownerRule)
@@ skipping 256 matching lines @@
 CSSStyleSheet* CSSStyleSheet::parentStyleSheet() const
 {
     return m_ownerRule ? m_ownerRule->parentStyleSheet() : 0;
 }
 
 Document* CSSStyleSheet::ownerDocument() const
 {
     const CSSStyleSheet* root = this;
     while (root->parentStyleSheet())
         root = root->parentStyleSheet();
-    return root->ownerNode() ? root->ownerNode()->document() : 0;
+    return root->ownerNode() ? &root->ownerNode()->document() : 0;
 }
 
 void CSSStyleSheet::clearChildRuleCSSOMWrappers()
 {
     m_childRuleCSSOMWrappers.clear();
 }
 
 }