Further tuning for AEC3 for initial echo suppression and handling of echo path changes

webrtc/modules/audio_processing/aec3/residual_echo_estimator.h

 /*
  *  Copyright (c) 2017 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 21 matching lines @@
                 const AecState& aec_state,
                 const FftBuffer& X_buffer,
                 const std::vector<std::array<float, kFftLengthBy2Plus1>>& H2,
                 const std::array<float, kFftLengthBy2Plus1>& E2_main,
                 const std::array<float, kFftLengthBy2Plus1>& E2_shadow,
                 const std::array<float, kFftLengthBy2Plus1>& S2_linear,
                 const std::array<float, kFftLengthBy2Plus1>& S2_fallback,
                 const std::array<float, kFftLengthBy2Plus1>& Y2,
                 std::array<float, kFftLengthBy2Plus1>* R2);
 
+  void HandleEchoPathChange(const EchoPathVariability& echo_path_variability);
+
  private:
   std::array<float, kFftLengthBy2Plus1> echo_path_gain_;
-  size_t active_render_counter_ = 0;
   size_t blocks_since_last_saturation_ = 1000;
 
   RTC_DISALLOW_COPY_AND_ASSIGN(ResidualEchoEstimator);
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_AUDIO_PROCESSING_AEC3_RESIDUAL_ECHO_ESTIMATOR_H_