Calculate the signal level on the media stream local audio track

content/renderer/media/webrtc/webrtc_local_audio_track_adapter.h

 // Copyright 2014 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 CONTENT_RENDERER_MEDIA_WEBRTC_WEBRTC_LOCAL_AUDIO_TRACK_ADAPTER_H_
 #define CONTENT_RENDERER_MEDIA_WEBRTC_WEBRTC_LOCAL_AUDIO_TRACK_ADAPTER_H_
 
 #include <vector>
 
 #include "base/memory/ref_counted.h"
@@ skipping 26 matching lines @@
   WebRtcLocalAudioTrackAdapter(
       const std::string& label,
       webrtc::AudioSourceInterface* track_source);
 
   virtual ~WebRtcLocalAudioTrackAdapter();
 
   void Initialize(WebRtcLocalAudioTrack* owner);
 
   std::vector<int> VoeChannels() const;
 
+  void SetSignalLevel(int signal_level);
+
  private:
   // webrtc::MediaStreamTrack implementation.
   virtual std::string kind() const OVERRIDE;
 
   // cricket::AudioCapturer implementation.
   virtual void AddChannel(int channel_id) OVERRIDE;
   virtual void RemoveChannel(int channel_id) OVERRIDE;
 
   // webrtc::AudioTrackInterface implementation.
   virtual webrtc::AudioSourceInterface* GetSource() const OVERRIDE;
   virtual cricket::AudioRenderer* GetRenderer() OVERRIDE;
 
   // Weak reference.
   WebRtcLocalAudioTrack* owner_;
 
   // The source of the audio track which handles the audio constraints.
   // TODO(xians): merge |track_source_| to |capturer_| in WebRtcLocalAudioTrack.
   talk_base::scoped_refptr<webrtc::AudioSourceInterface> track_source_;
 
   // A vector of WebRtc VoE channels that the capturer sends data to.
   std::vector<int> voe_channels_;
 
-  // Protects |voe_channels_|.
+  // The amplitude of the signal.
+  int signal_level_;

[tommi (sloooow) - chröme, 2014/02/27 08:39:43]

As is, this variable is never used.  Can we skip adding it in this cl?

[no longer working on chromium, 2014/02/28 08:16:25]

Done.

+
+  // Protects |voe_channels_|, |signal_level_|.
   mutable base::Lock lock_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_WEBRTC_WEBRTC_LOCAL_AUDIO_TRACK_ADAPTER_H_