Add OSX prefix, and be clear that this is OS X only API to avoid any expectation that this API may work elsewhere.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@62828 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/osx/core/private.h

@@ -755,7 +755,7 @@ public :
     long style, long extraStyle, const wxString& name  ) ;
     
     virtual void SetModified(bool WXUNUSED(modified)) { }
-    virtual bool GetModified() const { return false; }
+    virtual bool IsModified() const { return false; }
 
 protected :
     wxNonOwnedWindow*   m_wxPeer;