Added forced zero AEC output after call startup and echo path changes

webrtc/modules/audio_processing/aec3/suppression_gain.cc

 /*
  *  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 307 matching lines @@
   previous_masker_.fill(0.f);
 }
 
 void SuppressionGain::GetGain(
     const std::array<float, kFftLengthBy2Plus1>& nearend_power,
     const std::array<float, kFftLengthBy2Plus1>& residual_echo_power,
     const std::array<float, kFftLengthBy2Plus1>& comfort_noise_power,
     bool saturated_echo,
     const std::vector<std::vector<float>>& render,
     size_t num_capture_bands,
+    bool force_zero_gain,
     float* high_bands_gain,
     std::array<float, kFftLengthBy2Plus1>* low_band_gain) {
   RTC_DCHECK(high_bands_gain);
   RTC_DCHECK(low_band_gain);
 
+  if (force_zero_gain) {
+    previous_gain_squared_.fill(0.f);
+    std::copy(comfort_noise_power.begin() + 1, comfort_noise_power.end() - 1,
+              previous_masker_.begin());
+    low_band_gain->fill(0.f);
+    *high_bands_gain = 0.f;
+    return;
+  }
+
   // Choose margin to use.
   const float margin = saturated_echo ? 0.001f : 0.01f;
   switch (optimization_) {
 #if defined(WEBRTC_ARCH_X86_FAMILY)
     case Aec3Optimization::kSse2:
       aec3::ComputeGains_SSE2(
           nearend_power, residual_echo_power, comfort_noise_power, margin,
           &previous_gain_squared_, &previous_masker_, low_band_gain);
       break;
 #endif
@@ skipping 11 matching lines @@
         *std::min_element(low_band_gain->begin() + 32, low_band_gain->end());
 
     *high_bands_gain = std::min(*high_bands_gain, min_high_band_gain);
 
   } else {
     *high_bands_gain = 1.f;
   }
 }
 
 }  // namespace webrtc