Support audio output device enumeration and selection in PPAPI

ppapi/api/dev/ppb_device_ref_dev.idl

 /* Copyright (c) 2012 The Chromium Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 /**
  * This file defines the <code>PPB_DeviceRef_Dev</code> interface.
  */
 
 [generate_thunk]
@@ skipping 18 matching lines @@
     [in] uint32_t device_count,
     [in, size_is(device_count)] PP_Resource[] devices);
 
 /**
  * Device types.
  */
 [assert_size(4)]
 enum PP_DeviceType_Dev {
   PP_DEVICETYPE_DEV_INVALID = 0,
   PP_DEVICETYPE_DEV_AUDIOCAPTURE = 1,
-  PP_DEVICETYPE_DEV_VIDEOCAPTURE = 2
+  PP_DEVICETYPE_DEV_VIDEOCAPTURE = 2,
+  PP_DEVICETYPE_DEV_AUDIOOUTPUT = 3
 };
 
 interface PPB_DeviceRef_Dev {
   /**
    * Determines if the provided resource is a device reference.
    *
    * @param[in] resource A <code>PP_Resource</code> corresponding to a generic
    * resource.
    *
    * @return A <code>PP_Bool</code> that is <code>PP_TRUE</code> if the given
@@ skipping 17 matching lines @@
    *
    * @param[in] device_ref A <code>PP_Resource</code> corresponding to a device
    * reference.
    *
    * @return A <code>PP_Var</code> of type <code>PP_VARTYPE_STRING</code>
    * containing the name of the device if successful; a <code>PP_Var</code> of
    * type <code>PP_VARTYPE_UNDEFINED</code> if failed.
    */
   PP_Var GetName([in] PP_Resource device_ref);
 };