Add empty residual echo detector.

webrtc/modules/audio_processing/include/audio_processing.h

Index: webrtc/modules/audio_processing/include/audio_processing.h
diff --git a/webrtc/modules/audio_processing/include/audio_processing.h b/webrtc/modules/audio_processing/include/audio_processing.h
index b5d2aa22c0348cd4da2011fb7a67803d80862337..3f38d330e640ec7db65690e7da19f2bf554695e7 100644
--- a/webrtc/modules/audio_processing/include/audio_processing.h
+++ b/webrtc/modules/audio_processing/include/audio_processing.h
@@ -38,6 +38,7 @@ class ProcessingConfig;
 
 class EchoCancellation;
 class EchoControlMobile;
+class ResidualEchoDetector;

[peah-webrtc, 2016/10/13 10:11:17]

This forward can be removed.

[ivoc, 2016/10/13 10:31:25]

Done.

 class GainControl;
 class HighPassFilter;
 class LevelEstimator;
@@ -258,6 +259,9 @@ class AudioProcessing {
       // the allowed range is [-100, 0].
       float initial_peak_level_dbfs = -6.0206f;
     } level_controller;
+    struct ResidualEchoDetector {
+      bool enabled = false;
+    } residual_echo_detector;
   };
 
   // TODO(mgraczyk): Remove once all methods that use ChannelLayout are gone.