Pass camera facing info to audio client

chromeos/dbus/cras_audio_client.h

 // 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.
 
 #ifndef CHROMEOS_DBUS_CRAS_AUDIO_CLIENT_H_
 #define CHROMEOS_DBUS_CRAS_AUDIO_CLIENT_H_
 
 #include <stdint.h>
 
 #include "base/callback.h"
@@ skipping 31 matching lines @@
     // Called when active audio input node changed to new node with |node_id|.
     virtual void ActiveInputNodeChanged(uint64_t node_id);
 
     // Called when output node's volume changed.
     virtual void OutputNodeVolumeChanged(uint64_t node_id, int volume);
 
    protected:
     virtual ~Observer();
   };
 
+  enum VideoFacingMode { NONE = 0, USER, ENVIRONMENT };

[jennyz, 2017/01/18 00:01:37]

First: CrasAudioClient is a thin wrap for cras dbus API logic. It is not
appropriate to add other device logic here. A better place will be
CrasAudioHandler. 

Second: VideoFacingMode is better to be defined in the camera related class
instead of audio related class. '

Third: What is USER and ENVIRONMENT facing mode really mean?

[shenghao, 2017/01/18 10:41:12]

Moved to CrasAudioHandler
We already have a shared VideoFacingMode defined in //media/base. But since it
can't be included here, I am defining a new one, and I imagine that this
VideoFacingMode will only be used within CrasAudioHandler, so it seems more
natural to define it here. If you think there are other appropriate video
related classes in //chromeos world, please suggest.
Added comments. The naming is consistent with the enum in //media/base and in
Webkit.

+
   ~CrasAudioClient() override;
 
   // Adds and removes the observer.
   virtual void AddObserver(Observer* observer) = 0;
   virtual void RemoveObserver(Observer* observer) = 0;
   // Returns true if this object has the given observer.
   virtual bool HasObserver(const Observer* observer) const = 0;
 
+  virtual void OnVideoCaptureStarted(VideoFacingMode facing) {}

[jennyz, 2017/01/18 00:01:37]

Move this to CrasAudioHandler.

[shenghao, 2017/01/18 10:41:12]

Done.

+
   // GetVolumeStateCallback is used for GetVolumeState method. It receives
   // 2 arguments, |volume_state| which containing both input and  output volume
   // state data, and |success| which indicates whether or not the request
   // succeeded.
   typedef base::Callback<void(const VolumeState&, bool)> GetVolumeStateCallback;
 
   // GetNodesCallback is used for GetNodes method. It receives 2 arguments,
   // |audio_nodes| which containing a list of audio nodes data and
   // |success| which indicates whether or not the request succeeded.
   typedef base::Callback<void(const AudioNodeList&, bool)> GetNodesCallback;
@@ skipping 77 matching lines @@
   // Create() should be used instead.
   CrasAudioClient();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(CrasAudioClient);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_DBUS_CRAS_AUDIO_CLIENT_H_