Remove duplicated headers from core/

Source/core/editing/VisibleSelection.cpp

 /*
  * Copyright (C) 2004, 2005, 2006 Apple Computer, 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 13 matching lines @@
  */
 
 #include "config.h"
 #include "core/editing/VisibleSelection.h"
 
 #include "bindings/v8/ExceptionState.h"
 #include "core/dom/Document.h"
 #include "core/dom/Element.h"
 #include "core/dom/Range.h"
 #include "core/editing/TextIterator.h"
-#include "core/editing/VisiblePosition.h"
 #include "core/editing/VisibleUnits.h"
 #include "core/editing/htmlediting.h"
 #include "core/rendering/RenderObject.h"
 #include "platform/geometry/LayoutPoint.h"
 #include "wtf/Assertions.h"
 #include "wtf/text/CString.h"
 #include "wtf/text/StringBuilder.h"
 #include "wtf/unicode/CharacterNames.h"
 
 #ifndef NDEBUG
@@ skipping 695 matching lines @@
     sel.showTreeForThis();
 }
 
 void showTree(const WebCore::VisibleSelection* sel)
 {
     if (sel)
         sel->showTreeForThis();
 }
 
 #endif