Switching MediaStreamsManager from using AudioManager interface to AudioSystem one.

media/audio/audio_system_impl.cc

Index: media/audio/audio_system_impl.cc
diff --git a/media/audio/audio_system_impl.cc b/media/audio/audio_system_impl.cc
index a6c51a67d863a6086b33b9e470c97d1b8ebf4471..00ea330761b28861dc27bd55cdc39f9ffc1c8337 100644
--- a/media/audio/audio_system_impl.cc
+++ b/media/audio/audio_system_impl.cc
@@ -45,6 +45,18 @@ AudioParameters GetOutputParametersOnDeviceThread(
              : audio_manager->GetOutputStreamParameters(device_id);
 }
 
+AudioDeviceDescriptions GetDeviceDescriptionsOnDeviceThread(
+    AudioManager* audio_manager,
+    bool for_input) {
+  DCHECK(audio_manager->GetTaskRunner()->BelongsToCurrentThread());
+  AudioDeviceDescriptions descriptions;
+  if (for_input)
+    audio_manager->GetAudioInputDeviceDescriptions(&descriptions);
+  else
+    audio_manager->GetAudioOutputDeviceDescriptions(&descriptions);
+  return descriptions;
+}
+
 }  // namespace
 
 AudioSystemImpl::AudioSystemImpl(AudioManager* audio_manager)
@@ -109,6 +121,24 @@ void AudioSystemImpl::HasInputDevices(OnBoolCallback on_has_devices_cb) const {
       std::move(on_has_devices_cb));
 }
 
+void AudioSystemImpl::GetDeviceDescriptions(
+    OnDeviceDescriptionsCallback on_descriptions_cp,
+    bool for_input) {
+  if (GetTaskRunner()->BelongsToCurrentThread()) {
+    GetTaskRunner()->PostTask(
+        FROM_HERE, base::Bind(on_descriptions_cp,
+                              base::Passed(GetDeviceDescriptionsOnDeviceThread(
+                                  audio_manager_, for_input))));
+    return;
+  }
+
+  base::PostTaskAndReplyWithResult(
+      GetTaskRunner(), FROM_HERE,
+      base::Bind(&GetDeviceDescriptionsOnDeviceThread,
+                 base::Unretained(audio_manager_), for_input),
+      std::move(on_descriptions_cp));
+}
+
 AudioManager* AudioSystemImpl::GetAudioManager() const {
   return audio_manager_;
 }