/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
/*
 * For more information on this interface please see
 * https://html.spec.whatwg.org/multipage/#beforeunloadevent
 */

[Exposed=Window]
interface BeforeUnloadEvent : Event {
  attribute DOMString returnValue;
};