Have Document::markers() return a reference

Source/core/dom/Document.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
@@ skipping 765 matching lines @@
     void setBody(PassRefPtr<HTMLElement>, ExceptionState&);
 
     HTMLHeadElement* head();
 
     // Decide which element is to define the viewport's overflow policy. If |rootStyle| is set, use
     // that as the style for the root element, rather than obtaining it on our own. The reason for
     // this is that style may not have been associated with the elements yet - in which case it may
     // have been calculated on the fly (without associating it with the actual element) somewhere.
     Element* viewportDefiningElement(RenderStyle* rootStyle = 0) const;
 
-    DocumentMarkerController* markers() const { return m_markers.get(); }
+    DocumentMarkerController& markers() const { return *m_markers; }
 
     bool directionSetOnDocumentElement() const { return m_directionSetOnDocumentElement; }
     bool writingModeSetOnDocumentElement() const { return m_writingModeSetOnDocumentElement; }
     void setDirectionSetOnDocumentElement(bool b) { m_directionSetOnDocumentElement = b; }
     void setWritingModeSetOnDocumentElement(bool b) { m_writingModeSetOnDocumentElement = b; }
 
     bool execCommand(const String& command, bool userInterface = false, const String& value = String());
     bool queryCommandEnabled(const String& command);
     bool queryCommandIndeterm(const String& command);
     bool queryCommandState(const String& command);
@@ skipping 599 matching lines @@
 inline bool Node::isDocumentNode() const
 {
     return this == document();
 }
 
 Node* eventTargetNodeForDocument(Document*);
 
 } // namespace WebCore
 
 #endif // Document_h