Add a placeholder stat for logging the estimated residual echo likelihood.

webrtc/api/mediastreaminterface.h

 /*
  *  Copyright 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 187 matching lines @@
                             aec_quality_min(0.0),
                             echo_delay_std_ms(0),
                             aec_divergent_filter_fraction(0.0) {}
     ~AudioProcessorStats() {}
 
     bool typing_noise_detected;
     int echo_return_loss;
     int echo_return_loss_enhancement;
     int echo_delay_median_ms;
     float aec_quality_min;
     int echo_delay_std_ms;

[the sun, 2016/10/19 18:27:06]

While you're poking around, why isn't echo_delay_std_ms next to
echo_delay_media_ms?

[ivoc, 2016/10/20 14:28:12]

It is now.

+    float residual_echo_likelihood = 0.0f;

[the sun, 2016/10/19 18:27:06]

Initialize all fields in the same way, please - in other words change the old
ones or add the new one to the initializer list.

[ivoc, 2016/10/20 14:28:12]

Done.

     float aec_divergent_filter_fraction;
   };
 
   // Get audio processor statistics.
   virtual void GetStats(AudioProcessorStats* stats) = 0;
 
  protected:
   virtual ~AudioProcessorInterface() {}
 };
 
@@ skipping 44 matching lines @@
   virtual bool RemoveTrack(AudioTrackInterface* track) = 0;
   virtual bool RemoveTrack(VideoTrackInterface* track) = 0;
 
  protected:
   virtual ~MediaStreamInterface() {}
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_API_MEDIASTREAMINTERFACE_H_