[bindings] Remove custom bindings required for Location.valueOf

Source/core/frame/Location.idl

 /*
  * Copyright (C) 2008 Apple 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
@@ skipping 37 matching lines @@
     [SetterCallWith=(ActiveWindow,FirstWindow)] attribute DOMString port;
     [SetterCallWith=(ActiveWindow,FirstWindow)] attribute DOMString pathname;
     [SetterCallWith=(ActiveWindow,FirstWindow)] attribute DOMString search;
     [SetterCallWith=(ActiveWindow,FirstWindow)] attribute DOMString hash;
 
     readonly attribute DOMString origin;
 
     [Unforgeable] readonly attribute DOMStringList ancestorOrigins;
 
     [NotEnumerable, Unforgeable, ImplementedAs=href] DOMString toString();
-    [NotEnumerable, Custom, Unforgeable] any valueOf();
+    [NotEnumerable, CallWith=ThisValue, Unforgeable] any valueOf();
 };