Handle audio device changes on Mac

media/audio/mac/audio_manager_mac.cc

 // 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.
 
 #include <CoreAudio/AudioHardware.h>
 
 #include <string>
 
+#include "base/bind.h"
 #include "base/command_line.h"
 #include "base/mac/mac_logging.h"
 #include "base/mac/scoped_cftyperef.h"
 #include "base/sys_string_conversions.h"
+#include "media/audio/mac/audio_device_listener_mac.h"
 #include "media/audio/mac/audio_input_mac.h"
 #include "media/audio/mac/audio_low_latency_input_mac.h"
 #include "media/audio/mac/audio_low_latency_output_mac.h"
 #include "media/audio/mac/audio_manager_mac.h"
 #include "media/audio/mac/audio_output_mac.h"
 #include "media/audio/mac/audio_synchronized_mac.h"
 #include "media/audio/mac/audio_unified_mac.h"
+#include "media/base/bind_to_loop.h"
 #include "media/base/limits.h"
 #include "media/base/media_switches.h"
 
 namespace media {
 
 // Maximum number of output streams that can be open simultaneously.
 static const int kMaxOutputStreams = 50;
 
 static bool HasAudioHardware(AudioObjectPropertySelector selector) {
   AudioDeviceID output_device_id = kAudioObjectUnknown;
@@ skipping 195 matching lines @@
   if (result) {
     OSSTATUS_DLOG(WARNING, result) << "Unable to query device " << device_id
                                    << " for AudioDeviceID";
   }
 
   return audio_device_id;
 }
 
 AudioManagerMac::AudioManagerMac() {
   SetMaxOutputStreamsAllowed(kMaxOutputStreams);
+
+  output_device_listener_.reset(new AudioDeviceListenerMac(BindToLoop(

[DaleCurtis, 2012/10/29 01:58:45]

You need to do this in the InitializeOnAudioThread() method, you can't pass
"this" out to another thread during construction; it'll lead to races.

Which means you'll need to follow the same pattern as AUdioManagerWin to keep
thread checker happy.

[sail, 2012/10/29 04:21:46]

Done.

+      GetMessageLoop(),
+      base::Bind(&AudioManagerMac::NotifyAllOutputDeviceChangeListeners,
+                 base::Unretained(this)))));
 }
 
 AudioManagerMac::~AudioManagerMac() {
   Shutdown();
 }
 
 bool AudioManagerMac::HasAudioOutputDevices() {
   return HasAudioHardware(kAudioHardwarePropertyDefaultOutputDevice);
 }
 
@@ skipping 58 matching lines @@
     stream = new AUAudioInputStream(this, params, audio_device_id);
 
   return stream;
 }
 
 AudioManager* CreateAudioManager() {
   return new AudioManagerMac();
 }
 
 }  // namespace media