Add AudioManager::GetAudioOutputDeviceNames and implement for pulseaudio.

media/audio/audio_manager_base.cc

Index: media/audio/audio_manager_base.cc
diff --git a/media/audio/audio_manager_base.cc b/media/audio/audio_manager_base.cc
index 1218d1e0a76fa7e45123226733812e80aff7e4c3..2f9ccad03b94e367ca68aafc237457df4d1e350d 100644
--- a/media/audio/audio_manager_base.cc
+++ b/media/audio/audio_manager_base.cc
@@ -309,7 +309,13 @@ void AudioManagerBase::ShowAudioInputSettings() {
 }
 
 void AudioManagerBase::GetAudioInputDeviceNames(
-    media::AudioDeviceNames* device_names) {
+    AudioDeviceNames* device_names) {
+}
+
+void AudioManagerBase::GetAudioOutputDeviceNames(
+    AudioDeviceNames* device_names) {
+  // TODO(joi): Remove this and keep pure virtual once implemented everywhere.
+  NOTIMPLEMENTED();
 }
 
 void AudioManagerBase::ReleaseOutputStream(AudioOutputStream* stream) {