Reland review 34393006: Refactor MediaStreamManager to not output real device id.

media/audio/mock_audio_manager.cc

Index: media/audio/mock_audio_manager.cc
diff --git a/media/audio/mock_audio_manager.cc b/media/audio/mock_audio_manager.cc
index a164332a64a67afc49c3f145b2863251c146c72f..6b54be27c26c49659382c7e72b3899c734eb40cf 100644
--- a/media/audio/mock_audio_manager.cc
+++ b/media/audio/mock_audio_manager.cc
@@ -34,6 +34,11 @@ void MockAudioManager::ShowAudioInputSettings() {
 
 void MockAudioManager::GetAudioInputDeviceNames(
     AudioDeviceNames* device_names) {
+  DCHECK(device_names->empty());
+  device_names->push_back(media::AudioDeviceName("fake_device_name_1",
+                                                 "fake_device_id_1"));
+  device_names->push_back(media::AudioDeviceName("fake_device_name_2",
+                                                 "fake_device_id_2"));
 }
 
 void MockAudioManager::GetAudioOutputDeviceNames(