Major updates to the echo removal functionality in AEC3

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 12 matching lines @@
 
 namespace webrtc {
 
 class ResidualEchoEstimator {
  public:
   ResidualEchoEstimator();
   ~ResidualEchoEstimator();
 
   void Estimate(bool using_subtractor_output,
                 const AecState& aec_state,
-                const RenderBuffer& 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 RenderBuffer& render_buffer,
                 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 blocks_since_last_saturation_ = 1000;
+  std::array<float, kFftLengthBy2Plus1> R2_old_;
+  std::array<int, kFftLengthBy2Plus1> R2_hold_counter_;
 
   RTC_DISALLOW_COPY_AND_ASSIGN(ResidualEchoEstimator);
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_AUDIO_PROCESSING_AEC3_RESIDUAL_ECHO_ESTIMATOR_H_