Add [OverrideBuiltins] to HTMLCollection IDL interface

Source/core/html/HTMLCollection.idl

 /*
  * Copyright (C) 2006, 2007, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Samuel Weinig <sam.weinig@gmail.com>
  *
  * 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.
  */
 
 [
     Custom=Wrap,
     DependentLifetime,
     SetWrapperReferenceFrom=ownerNode,
+    OverrideBuiltins

[Inactive, 2014/02/05 21:07:02]

If you want, I can file a bug and add a FIXME here to explain that
OverrideBuiltins should be removed once the performance impact of doing so
becomes more acceptable.

[Inactive, 2014/02/05 21:35:14]

Done.

 ] interface HTMLCollection {
     readonly attribute unsigned long length;
     getter Element item([Default=Undefined] optional unsigned long index);
     Element namedItem([Default=Undefined] optional DOMString name);
     [NotEnumerable, ImplementedAs=namedItem] getter Element ([Default=Undefined] optional DOMString name);
 };