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

third_party/WebKit/Source/modules/indexeddb/IDBKeyRange.idl

 /*
  * Copyright (C) 2010 Google 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
  *     notice, this list of conditions and the following disclaimer in the
  *     documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 // http://www.w3.org/TR/IndexedDB/#idl-def-IDBKeyRange
 
 [
     Exposed=(Window,Worker),
-    GarbageCollected
 ] interface IDBKeyRange {
     [ImplementedAs=lowerValue, CallWith=ScriptState] readonly attribute any lower;
     [ImplementedAs=upperValue, CallWith=ScriptState] readonly attribute any upper;
     readonly attribute boolean lowerOpen;
     readonly attribute boolean upperOpen;
 
     [CallWith=ExecutionContext, RaisesException] static IDBKeyRange only(any value);
     [CallWith=ExecutionContext, RaisesException] static IDBKeyRange lowerBound(any bound, optional boolean open = false);
     [CallWith=ExecutionContext, RaisesException] static IDBKeyRange upperBound(any bound, optional boolean open = false);
     [CallWith=ExecutionContext, RaisesException] static IDBKeyRange bound(any lower, any upper, optional boolean lowerOpen = false, optional boolean upperOpen = false);
 
     [CallWith=ExecutionContext, RaisesException, RuntimeEnabled=IndexedDBExperimental] boolean includes(any key);
 };