Oilpan: move DOM string collection objects to the Oilpan heap.

Source/core/dom/NamedNodeMap.idl

 /*
  * Copyright (C) 2006 Samuel Weinig <sam.weinig@gmail.com>
  * Copyright (C) 2007, 2009 Apple Inc. All rights reserved.
  *
  * 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.
  */
 
 [
     SetWrapperReferenceFrom=element,
+    WillBeGarbageCollected,
 ] interface NamedNodeMap {
 
     [MeasureAs=NamedNodeMapGetNamedItem] Node getNamedItem([Default=Undefined] optional DOMString name);
     [NotEnumerable, ImplementedAs=getNamedItem] getter Node ([Default=Undefined] optional DOMString name);
 
     [RaisesException, CustomElementCallbacks, MeasureAs=NamedNodeMapSetNamedItem] Node setNamedItem([Default=Undefined] optional Node node);
 
     [RaisesException, CustomElementCallbacks, MeasureAs=NamedNodeMapRemoveNamedItem] Node removeNamedItem([Default=Undefined] optional DOMString name);
 
     [MeasureAs=NamedNodeMapItem] getter Node item([Default=Undefined] optional unsigned long index);
 
     readonly attribute unsigned long length;
 
 
     // Introduced in DOM Level 2:
 
     [MeasureAs=NamedNodeMapGetNamedItemNS] Node getNamedItemNS([TreatNullAs=NullString, Default=Undefined] optional DOMString namespaceURI,
                                                                [Default=Undefined] optional DOMString localName);
 
     [RaisesException, CustomElementCallbacks, MeasureAs=NamedNodeMapSetNamedItemNS] Node setNamedItemNS([Default=Undefined] optional Node node);
 
     [RaisesException, CustomElementCallbacks, MeasureAs=NamedNodeMapRemoveNamedItemNS] Node removeNamedItemNS([TreatNullAs=NullString, Default=Undefined] optional DOMString namespaceURI,
                                                                                                               [Default=Undefined] optional DOMString localName);
 
 };