Pass camera facing info to audio client

chromeos/audio/cras_audio_handler.h

Index: chromeos/audio/cras_audio_handler.h
diff --git a/chromeos/audio/cras_audio_handler.h b/chromeos/audio/cras_audio_handler.h
index 1408f061f5d103fc56b55aed917072477056c511..dce24683ba91a84e2df7517eaf8b6fe709a1619e 100644
--- a/chromeos/audio/cras_audio_handler.h
+++ b/chromeos/audio/cras_audio_handler.h
@@ -26,13 +26,28 @@ namespace chromeos {
 
 class AudioDevicesPrefHandler;
 
+enum class VideoFacingMode {
+  NONE = 0,
+  // Video device is facing the user. I.e. front camera.
+  USER,
+  // Video device is facing the environment. I.e. back camera.
+  ENVIRONMENT
+};
+
+class VideoCaptureObserver {
+ public:
+  virtual void OnVideoCaptureStarted(VideoFacingMode facing) = 0;
+  virtual void OnVideoCaptureStopped(VideoFacingMode facing) = 0;
+};

[jennyz, 2017/02/03 22:44:13]

It is kind of a little weird to define a VideoCaptureObserver in
CrasAudioHandler. Can you put VideorCaptureObserver in the video related file
and use Observer pattern, and use AddObserver/RemoveObserver to either add or
remove CrasAudioHandler object to the Video object that broadcast the video
events?

[shenghao, 2017/02/08 02:07:09]

Talked offline with Jenny. She is trying to find a better place. Otherwise we
will keep it as is.

[jennyz, 2017/02/08 22:21:33]

Have you tried to make a separate target for the media::VideoCaptureObserver
class, instead of building it with //media/base? By making it a separate class,
you can have chromeos depend on this new target, instead of //media/base, then
it breaks the cyclical dependency issue you had before. It will simplify the
code a lot.

[shenghao, 2017/02/09 02:08:51]

Removed this part.

+
 class CHROMEOS_EXPORT CrasAudioHandler : public CrasAudioClient::Observer,
                                          public AudioPrefObserver,
-                                         public SessionManagerClient::Observer {
+                                         public SessionManagerClient::Observer,
+                                         public VideoCaptureObserver {
  public:
-  typedef std::priority_queue<AudioDevice,
-                              std::vector<AudioDevice>,
-                              AudioDeviceCompare> AudioDevicePriorityQueue;
+  typedef std::
+      priority_queue<AudioDevice, std::vector<AudioDevice>, AudioDeviceCompare>
+          AudioDevicePriorityQueue;
   typedef std::vector<uint64_t> NodeIdList;
 
   // Volume change reasons that are not user-initiated.
@@ -103,6 +118,10 @@ class CHROMEOS_EXPORT CrasAudioHandler : public CrasAudioClient::Observer,
   // Gets the global instance. Initialize must be called first.
   static CrasAudioHandler* Get();
 
+  // Overrides VideoCaptureObserver.
+  void OnVideoCaptureStarted(VideoFacingMode facing) override;
+  void OnVideoCaptureStopped(VideoFacingMode facing) override;
+
   // Adds an audio observer.
   void AddAudioObserver(AudioObserver* observer);