Reimplement the AlsaPcmOutputStream and fix the threading issues.

media/media.gyp

 # Copyright (c) 2009 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,
   },
   'includes': [
     '../build/common.gypi',
@@ skipping 20 matching lines @@
       'sources': [
         'audio/audio_output.h',
         'audio/audio_util.cc',
         'audio/audio_util.h',
         'audio/fake_audio_output_stream.cc',
         'audio/fake_audio_output_stream.h',
         'audio/linux/audio_manager_linux.cc',
         'audio/linux/audio_manager_linux.h',
         'audio/linux/alsa_output.cc',
         'audio/linux/alsa_output.h',
+        'audio/linux/alsa_wrapper.cc',
+        'audio/linux/alsa_wrapper.h',
         'audio/mac/audio_manager_mac.cc',
         'audio/mac/audio_manager_mac.h',
         'audio/mac/audio_output_mac.cc',
         'audio/mac/audio_output_mac.h',
         'audio/simple_sources.cc',
         'audio/simple_sources.h',
         'audio/win/audio_manager_win.h',
         'audio/win/audio_output_win.cc',
         'audio/win/waveout_output_win.cc',
         'audio/win/waveout_output_win.h',
@@ skipping 95 matching lines @@
       'msvs_guid': 'C8C6183C-B03C-11DD-B471-DFD256D89593',
       'dependencies': [
         'media',
         '../base/base.gyp:base',
         '../testing/gmock.gyp:gmock',
         '../testing/gtest.gyp:gtest',
         '../third_party/ffmpeg/ffmpeg.gyp:ffmpeg',
       ],
       'sources': [
         'audio/audio_util_unittest.cc',
+        'audio/linux/alsa_output_unittest.cc',
         'audio/mac/audio_output_mac_unittest.cc',
         'audio/simple_sources_unittest.cc',
         'audio/win/audio_output_win_unittest.cc',
         'base/buffer_queue_unittest.cc',
         'base/clock_impl_unittest.cc',
         'base/data_buffer_unittest.cc',
         'base/mock_ffmpeg.cc',
         'base/mock_ffmpeg.h',
         'base/mock_filter_host.h',
         'base/mock_filters.cc',
@@ skipping 85 matching lines @@
           'msvs_settings': {
             'VCLinkerTool': {
               'SubSystem': '2',         # Set /SUBSYSTEM:WINDOWS
             },
           },
         },
       ],
     }],
   ],
 }