Implement GetAudioOutputDeviceNames for Mac OS X.

BUG=276894
R=tommi@chromium.org

Review URL: https://codereview.chromium.org/24072002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@222217 0039d316-1c4b-4281-b951-d872f2087c98

media/audio/audio_manager_unittest.cc

@@ -32,6 +32,8 @@ void GetAudioOutputDeviceNamesImpl(AudioManager* audio_manager) {
 }
 
 TEST(AudioManagerTest, GetAudioOutputDeviceNames) {
+  // On Linux, we may be able to test both the Alsa and Pulseaudio
+  // versions of the audio manager.
 #if defined(USE_PULSEAUDIO)
   {
     VLOG(2) << "Testing AudioManagerPulse.";
@@ -49,6 +51,12 @@ TEST(AudioManagerTest, GetAudioOutputDeviceNames) {
     GetAudioOutputDeviceNamesImpl(alsa_audio_manager.get());
   }
 #endif  // defined(USE_ALSA)
+
+#if defined(OS_MACOSX)
+  VLOG(2) << "Testing platform-default AudioManager.";
+  scoped_ptr<AudioManager> audio_manager(AudioManager::Create());
+  GetAudioOutputDeviceNamesImpl(audio_manager.get());
+#endif  // defined(OS_MACOSX)
 }
 
 }  // namespace media

media/audio/mac/audio_manager_mac.cc

@@ -81,6 +81,8 @@ bool AudioManagerMac::HasUnifiedDefaultIO() {
   return input_id == output_id;
 }
 
+// Retrieves information on audio devices, and prepends the default
+// device to the list if the list is non-empty.
 static void GetAudioDeviceInfo(bool is_input,
                                media::AudioDeviceNames* device_names) {
   // Query the number of total devices.
@@ -173,6 +175,16 @@ static void GetAudioDeviceInfo(bool is_input,
     if (name)
       CFRelease(name);
   }
+
+  if (!device_names->empty()) {
+    // Prepend the default device to the list since we always want it to be
+    // on the top of the list for all platforms. There is no duplicate
+    // counting here since the default device has been abstracted out before.
+    media::AudioDeviceName name;
+    name.device_name = AudioManagerBase::kDefaultDeviceName;
+    name.unique_id = AudioManagerBase::kDefaultDeviceId;
+    device_names->push_front(name);
+  }
 }
 
 static AudioDeviceID GetAudioDeviceIdByUId(bool is_input,
@@ -396,15 +408,12 @@ void AudioManagerMac::GetAudioInputDeviceNames(
     media::AudioDeviceNames* device_names) {
   DCHECK(device_names->empty());
   GetAudioDeviceInfo(true, device_names);
-  if (!device_names->empty()) {
-    // Prepend the default device to the list since we always want it to be
-    // on the top of the list for all platforms. There is no duplicate
-    // counting here since the default device has been abstracted out before.
-    media::AudioDeviceName name;
-    name.device_name = AudioManagerBase::kDefaultDeviceName;
-    name.unique_id =  AudioManagerBase::kDefaultDeviceId;
-    device_names->push_front(name);
-  }
+}
+
+void AudioManagerMac::GetAudioOutputDeviceNames(
+    media::AudioDeviceNames* device_names) {
+  DCHECK(device_names->empty());
+  GetAudioDeviceInfo(false, device_names);
 }
 
 AudioParameters AudioManagerMac::GetInputStreamParameters(

media/audio/mac/audio_manager_mac.h

@@ -29,6 +29,8 @@ class MEDIA_EXPORT AudioManagerMac : public AudioManagerBase {
   virtual bool HasAudioInputDevices() OVERRIDE;
   virtual void GetAudioInputDeviceNames(media::AudioDeviceNames* device_names)
       OVERRIDE;
+  virtual void GetAudioOutputDeviceNames(media::AudioDeviceNames* device_names)
+      OVERRIDE;
   virtual AudioParameters GetInputStreamParameters(
       const std::string& device_id) OVERRIDE;