Pass camera facing info to audio client

chromeos/audio/cras_audio_handler.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chromeos/audio/cras_audio_handler.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 108 matching lines @@
   return g_cras_audio_handler != NULL;
 }
 
 // static
 CrasAudioHandler* CrasAudioHandler::Get() {
   CHECK(g_cras_audio_handler)
       << "CrasAudioHandler::Get() called before Initialize().";
   return g_cras_audio_handler;
 }
 
+void CrasAudioHandler::OnVideoCaptureStarted(VideoFacingMode facing) {
+  // TODO(jennyz): Switch active audio device according to video facing.
+}
+
+void CrasAudioHandler::OnVideoCaptureStopped(VideoFacingMode facing) {
+  // TODO(jennyz): Switch active audio device according to video facing.

[jennyz, 2017/01/26 00:26:11]

Upon receiving video capture stopped notification, how should audio switch
device according to video facing? Will there be another active camera, or both
camera become inactive. How can we find out?

[shenghao, 2017/01/29 10:21:01]

Talked offline with Jenny.

+}
+
 void CrasAudioHandler::AddAudioObserver(AudioObserver* observer) {
   observers_.AddObserver(observer);
 }
 
 void CrasAudioHandler::RemoveAudioObserver(AudioObserver* observer) {
   observers_.RemoveObserver(observer);
 }
 
 bool CrasAudioHandler::HasKeyboardMic() {
   return GetKeyboardMic() != NULL;
@@ skipping 1270 matching lines @@
                      hdmi_rediscover_grace_period_duration_in_ms_),
       this, &CrasAudioHandler::UpdateAudioAfterHDMIRediscoverGracePeriod);
 }
 
 void CrasAudioHandler::SetHDMIRediscoverGracePeriodForTesting(
     int duration_in_ms) {
   hdmi_rediscover_grace_period_duration_in_ms_ = duration_in_ms;
 }
 
 }  // namespace chromeos