Remove DOMSelection::setPosition

Source/core/page/Selection.idl

 /*
  * Copyright (C) 2007 Apple Inc.  All rights reserved.
  * Copyright (C) 2009 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.
@@ skipping 58 matching lines @@
     // IE's type accessor returns "none", "text" and "control"
     readonly attribute DOMString type;
 
     void modify([Default=Undefined] optional DOMString alter,
                 [Default=Undefined] optional DOMString direction,
                 [Default=Undefined] optional DOMString granularity);
     [RaisesException] void setBaseAndExtent([Default=Undefined] optional Node baseNode,
                           [Default=Undefined] optional long baseOffset,
                           [Default=Undefined] optional Node extentNode,
                           [Default=Undefined] optional long extentOffset);
-    [RaisesException] void setPosition([Default=Undefined] optional Node node,
+    [RaisesException, ImplementedAs=collapse] void setPosition([Default=Undefined] optional Node node,
                      [Default=Undefined] optional long offset);
 
     // IE extentions
     // http://msdn.microsoft.com/en-us/library/ms535869(VS.85).aspx
     void empty();
 };