The Tor Browser / file revision

 /* 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 http://mozilla.org/MPL/2.0/.

  */

 /*

  * Allow application can control acoustic sound output through speaker.

  * Reference https://wiki.mozilla.org/WebAPI/SpeakerManager

  */

 [Constructor()]

 interface MozSpeakerManager : EventTarget {

   /* query the speaker status */

   readonly attribute boolean speakerforced;

   /* force device device's acoustic sound output through speaker */

   attribute boolean forcespeaker;

   /* this event will be fired when device's speaker forced status change */

   attribute EventHandler onspeakerforcedchange;

 };