Update WebKit IDLs after chrome roll.

xml/XPathResult.idl

 /*
  * Copyright (C) 2006 Apple Computer, Inc.
  *
  * 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,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 
 [
-    JSCustomMarkFunction,
     ImplementationLacksVTable
 ] interface XPathResult {
     const unsigned short ANY_TYPE                       = 0;
     const unsigned short NUMBER_TYPE                    = 1;
     const unsigned short STRING_TYPE                    = 2;
     const unsigned short BOOLEAN_TYPE                   = 3;
     const unsigned short UNORDERED_NODE_ITERATOR_TYPE   = 4;
     const unsigned short ORDERED_NODE_ITERATOR_TYPE     = 5;
     const unsigned short UNORDERED_NODE_SNAPSHOT_TYPE   = 6;
     const unsigned short ORDERED_NODE_SNAPSHOT_TYPE     = 7;
@@ skipping 16 matching lines @@
     readonly attribute boolean         invalidIteratorState;
     readonly attribute unsigned long   snapshotLength
         getter raises (DOMException);
         
     Node iterateNext()
         raises (DOMException);
     Node snapshotItem(in [Optional=DefaultIsUndefined] unsigned long index)
         raises (DOMException);
 };