Disable AudioOutputMixer.

media/media.gyp

 # 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.
 
 {
   'variables': {
     'chromium_code': 1,
     # Override to dynamically link the PulseAudio library.
     'use_pulseaudio%': 0,
     # Override to dynamically link the cras (ChromeOS audio) library.
@@ skipping 51 matching lines @@
         'audio/audio_output_controller.cc',
         'audio/audio_output_controller.h',
         'audio/audio_output_device.cc',
         'audio/audio_output_device.h',
         'audio/audio_output_dispatcher.cc',
         'audio/audio_output_dispatcher.h',
         'audio/audio_output_dispatcher_impl.cc',
         'audio/audio_output_dispatcher_impl.h',
         'audio/audio_output_ipc.cc',
         'audio/audio_output_ipc.h',
-        'audio/audio_output_mixer.cc',
-        'audio/audio_output_mixer.h',
         'audio/audio_output_proxy.cc',
         'audio/audio_output_proxy.h',
         'audio/audio_parameters.cc',
         'audio/audio_parameters.h',
         'audio/audio_util.cc',
         'audio/audio_util.h',
         'audio/cross_process_notification.cc',
         'audio/cross_process_notification.h',
         'audio/cross_process_notification_posix.cc',
         'audio/cross_process_notification_win.cc',
@@ skipping 1079 matching lines @@
             'media',
           ],
           'sources': [
             'tools/media_bench/media_bench.cc',
           ],
         },
       ],
     }]
   ],
 }