Implement GetAudioOutputDevices for remaining platforms, consolidate tests.

media/audio/cras/audio_manager_cras.cc

Index: media/audio/cras/audio_manager_cras.cc
diff --git a/media/audio/cras/audio_manager_cras.cc b/media/audio/cras/audio_manager_cras.cc
index 276487557e0d606fff86f4543d347c597af89ad7..7ef65b2fd920fb36753bafc7d8e52f4afefd9538 100644
--- a/media/audio/cras/audio_manager_cras.cc
+++ b/media/audio/cras/audio_manager_cras.cc
@@ -16,6 +16,15 @@
 
 namespace media {
 
+static void AddDefaultDevice(AudioDeviceNames* device_names) {
+  DCHECK(device_names->empty());
+
+  // Cras will route audio from a proper physical device automatically.
+  device_names->push_back(
+      AudioDeviceName(AudioManagerBase::kDefaultDeviceName,
+                      AudioManagerBase::kDefaultDeviceId));
+}
+
 // Maximum number of output streams that can be open simultaneously.
 static const int kMaxOutputStreams = 50;
 
@@ -45,10 +54,13 @@ void AudioManagerCras::ShowAudioInputSettings() {
 }
 
 void AudioManagerCras::GetAudioInputDeviceNames(
-    media::AudioDeviceNames* device_names) {
-  DCHECK(device_names->empty());
-  GetCrasAudioInputDevices(device_names);
-  return;
+    AudioDeviceNames* device_names) {
+  AddDefaultDevice(device_names);
+}
+
+void AudioManagerCras::GetAudioOutputDeviceNames(
+    AudioDeviceNames* device_names) {
+  AddDefaultDevice(device_names);
 }
 
 AudioParameters AudioManagerCras::GetInputStreamParameters(
@@ -61,14 +73,6 @@ AudioParameters AudioManagerCras::GetInputStreamParameters(
       kDefaultSampleRate, 16, kDefaultInputBufferSize);
 }
 
-void AudioManagerCras::GetCrasAudioInputDevices(
-    media::AudioDeviceNames* device_names) {
-  // Cras will route audio from a proper physical device automatically.
-  device_names->push_back(
-      AudioDeviceName(AudioManagerBase::kDefaultDeviceName,
-                      AudioManagerBase::kDefaultDeviceId));
-}
-
 AudioOutputStream* AudioManagerCras::MakeLinearOutputStream(
     const AudioParameters& params) {
   DCHECK_EQ(AudioParameters::AUDIO_PCM_LINEAR, params.format());