Fix incorrect API version information.

ppapi/api/ppb_audio.idl

 /* Copyright (c) 2011 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_Audio</code> interface, which provides
  * realtime stereo audio streaming capabilities.
  */
 
 label Chrome {
-  M13 = 0.6,
   M14 = 1.0
 };
 
 /**
  * <code>PPB_Audio_Callback</code> defines the type of an audio callback
  * function used to fill the audio buffer with data. Please see the
  * <code>Create()</code> function in the <code>PPB_Audio</code> interface for
  * more details on this callback.
  */
 typedef void PPB_Audio_Callback([out] mem_t sample_buffer,
@@ skipping 102 matching lines @@
    *
    * @return A PP_BOOL containing PP_TRUE if successful, otherwise PP_FALSE.
    * Also returns PP_TRUE (and is a no-op) if called while playback is already
    * stopped. If a callback is in progress, StopPlayback will block until the
    * callback completes.
    */
   PP_Bool StopPlayback(
       [in] PP_Resource audio);
 };