Use AudioStreamMonitor to control power save blocking.

chrome/chrome_browser.gypi

 # Copyright 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': {
     # All .cc, .h, .m, and .mm files under browser except for:
     # * tests and mocks.
     # * code below browser/chromeos
     # * code below browser/extensions
@@ skipping 621 matching lines @@
       'browser/mac/mac_startup_profiler.cc',
       'browser/mac/mac_startup_profiler.h',
       'browser/mac/master_prefs.h',
       'browser/mac/master_prefs.mm',
       'browser/mac/obsolete_system.cc',
       'browser/mac/obsolete_system.h',
       'browser/mac/relauncher.cc',
       'browser/mac/relauncher.h',
       'browser/mac/security_wrappers.cc',
       'browser/mac/security_wrappers.h',
-      'browser/media/audio_stream_monitor.cc',
-      'browser/media/audio_stream_monitor.h',
       'browser/media/cast_transport_host_filter.cc',
       'browser/media/cast_transport_host_filter.h',
       'browser/media/desktop_media_list.h',
       'browser/media/desktop_media_picker.h',
       'browser/media/desktop_streams_registry.cc',
       'browser/media/desktop_streams_registry.h',
       'browser/media/media_capture_devices_dispatcher.cc',
       'browser/media/media_capture_devices_dispatcher.h',
       'browser/media/media_device_id_salt.cc',
       'browser/media/media_device_id_salt.h',
@@ skipping 2916 matching lines @@
           'variables': {
             'proto_in_dir': 'browser/sync_file_system/drive_backend',
             'proto_out_dir': 'chrome/browser/sync_file_system/drive_backend',
           },
           'includes': [ '../build/protoc.gypi' ]
         },
       ],
     },],
   ],
 }