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

Source/core/svg/SVGStyleElement.cpp

 /*
  * Copyright (C) 2004, 2005 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007 Rob Buis <buis@kde.org>
  * Copyright (C) 2006 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Cameron McCormack <cam@mcc.id.au>
  *
  * 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 22 matching lines @@
     : SVGElement(tagName, document)
     , StyleElement(document, createdByParser)
     , m_svgLoadEventTimer(this, &SVGElement::svgLoadEventTimerFired)
 {
     ASSERT(hasTagName(SVGNames::styleTag));
     ScriptWrappable::init(this);
 }
 
 SVGStyleElement::~SVGStyleElement()
 {
-    StyleElement::clearDocumentData(document(), this);
+    StyleElement::clearDocumentData(&document(), this);
 }
 
 PassRefPtr<SVGStyleElement> SVGStyleElement::create(const QualifiedName& tagName, Document* document, bool createdByParser)
 {
     return adoptRef(new SVGStyleElement(tagName, document, createdByParser));
 }
 
 bool SVGStyleElement::disabled() const
 {
     if (!m_sheet)
@@ skipping 75 matching lines @@
 Node::InsertionNotificationRequest SVGStyleElement::insertedInto(ContainerNode* rootParent)
 {
     SVGElement::insertedInto(rootParent);
     if (rootParent->inDocument())
         return InsertionShouldCallDidNotifySubtreeInsertions;
     return InsertionDone;
 }
 
 void SVGStyleElement::didNotifySubtreeInsertions(ContainerNode* insertionPoint)
 {
-    StyleElement::processStyleSheet(document(), this);
+    StyleElement::processStyleSheet(&document(), this);
 }
 
 void SVGStyleElement::removedFrom(ContainerNode* rootParent)
 {
     SVGElement::removedFrom(rootParent);
     if (rootParent->inDocument())
-        StyleElement::removedFromDocument(document(), this);
+        StyleElement::removedFromDocument(&document(), this);
 }
 
 void SVGStyleElement::childrenChanged(bool changedByParser, Node* beforeChange, Node* afterChange, int childCountDelta)
 {
     SVGElement::childrenChanged(changedByParser, beforeChange, afterChange, childCountDelta);
     StyleElement::childrenChanged(this);
 }
 
 }