Remove code that is unused after ContextMenu cleanup

Source/core/page/Page.h

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * 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 119 matching lines @@
 
     void setMainFrame(PassRefPtr<Frame>);
     Frame* mainFrame() const { return m_mainFrame.get(); }
 
     bool openedByDOM() const;
     void setOpenedByDOM();
 
     // DEPRECATED. Use backForward() instead of the following 5 functions.
     bool goBack();
     bool goForward();
-    bool canGoBackOrForward(int distance) const;
     void goBackOrForward(int distance);
     int getHistoryLength();
 
     void goToItem(HistoryItem*);
 
     enum PageGroupType { PrivatePageGroup, SharedPageGroup };
     void setGroupType(PageGroupType);
     void clearPageGroup();
     PageGroup& group()
     {
@@ skipping 187 matching lines @@
 #endif
 
     OwnPtr<PageConsole> m_console;
 
     HashSet<MultisamplingChangedObserver*> m_multisamplingChangedObservers;
 };
 
 } // namespace WebCore
     
 #endif // Page_h