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

Source/core/inspector/InspectorStyleSheet.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 1740 matching lines @@
     return !es.hadException();
 }
 
 PassOwnPtr<Vector<unsigned> > InspectorStyleSheetForInlineStyle::lineEndings() const
 {
     return WTF::lineEndings(elementStyleText());
 }
 
 Document* InspectorStyleSheetForInlineStyle::ownerDocument() const
 {
-    return m_element->document();
+    return &m_element->document();
 }
 
 bool InspectorStyleSheetForInlineStyle::ensureParsedDataReady()
 {
     // The "style" property value can get changed indirectly, e.g. via element.style.borderWidth = "2px".
     const String& currentStyleText = elementStyleText();
     if (m_styleText != currentStyleText) {
         m_ruleSourceData.clear();
         m_styleText = currentStyleText;
         m_isStyleTextValid = true;
@@ skipping 36 matching lines @@
 
     if (m_styleText.isEmpty()) {
         RefPtr<CSSRuleSourceData> result = CSSRuleSourceData::create(CSSRuleSourceData::STYLE_RULE);
         result->ruleBodyRange.start = 0;
         result->ruleBodyRange.end = 0;
         return result.release();
     }
 
     RefPtr<MutableStylePropertySet> tempDeclaration = MutableStylePropertySet::create();
     RuleSourceDataList ruleSourceDataResult;
-    StyleSheetHandler handler(m_styleText, m_element->document(), m_element->document()->elementSheet()->contents(), &ruleSourceDataResult);
-    createCSSParser(m_element->document())->parseDeclaration(tempDeclaration.get(), m_styleText, &handler, m_element->document()->elementSheet()->contents());
+    StyleSheetHandler handler(m_styleText, &m_element->document(), m_element->document().elementSheet()->contents(), &ruleSourceDataResult);
+    createCSSParser(&m_element->document())->parseDeclaration(tempDeclaration.get(), m_styleText, &handler, m_element->document().elementSheet()->contents());
     return ruleSourceDataResult.first().release();
 }
 
 } // namespace WebCore