Have bindings layer assume and insist that all interface types are GCed.

third_party/WebKit/Source/core/xml/DOMParser.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
@@ skipping 12 matching lines @@
     "text/html",
     "text/xml",
     "application/xml",
     "application/xhtml+xml",
     "image/svg+xml"
 };
 
 [
     Constructor,
     ConstructorCallWith=Document,
-    GarbageCollected,
 ] interface DOMParser {
     [NewObject] Document parseFromString(DOMString str, SupportedType type);
 };