Add OSX aggregate audio device support for best performance.

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 cras (ChromeOS audio) library.
     'use_cras%': 0,
     # Option e.g. for Linux distributions to link pulseaudio directly
@@ skipping 118 matching lines @@
         'audio/linux/alsa_input.cc',
         'audio/linux/alsa_input.h',
         'audio/linux/alsa_output.cc',
         'audio/linux/alsa_output.h',
         'audio/linux/alsa_util.cc',
         'audio/linux/alsa_util.h',
         'audio/linux/alsa_wrapper.cc',
         'audio/linux/alsa_wrapper.h',
         'audio/linux/audio_manager_linux.cc',
         'audio/linux/audio_manager_linux.h',
+        'audio/mac/aggregate_device_manager.cc',
+        'audio/mac/aggregate_device_manager.h',
         'audio/mac/audio_auhal_mac.cc',
         'audio/mac/audio_auhal_mac.h',
         'audio/mac/audio_device_listener_mac.cc',
         'audio/mac/audio_device_listener_mac.h',
         'audio/mac/audio_input_mac.cc',
         'audio/mac/audio_input_mac.h',
         'audio/mac/audio_low_latency_input_mac.cc',
         'audio/mac/audio_low_latency_input_mac.h',
         'audio/mac/audio_low_latency_output_mac.cc',
         'audio/mac/audio_low_latency_output_mac.h',
@@ skipping 1540 matching lines @@
           ],
           'sources': [
             'base/simd/sinc_resampler_sse.cc',
             'base/simd/vector_math_sse.cc',
           ],
         }, # end of target media_sse
       ],
     }],
   ],
 }