Removed the timeout for the delay estimate quality.

webrtc/modules/audio_processing/aec3/render_delay_controller.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.
  */
 #include "webrtc/modules/audio_processing/aec3/render_delay_controller.h"
@@ skipping 24 matching lines @@
   void SetDelay(size_t render_delay) override;
   size_t GetDelay(const DownsampledRenderBuffer& render_buffer,
                   rtc::ArrayView<const float> capture) override;
   rtc::Optional<size_t> AlignmentHeadroomSamples() const override {
     return headroom_samples_;
   }
 
  private:
   static int instance_count_;
   std::unique_ptr<ApmDataDumper> data_dumper_;
-  size_t delay_ = 0;

[peah-webrtc, 2017/09/11 12:31:42]

This is a bit of an unrelated change, but I include it anyway. It is a
correction that complies to how it is done after a reset.

+  size_t delay_ = kMinEchoPathDelayBlocks;
   EchoPathDelayEstimator delay_estimator_;
   size_t blocks_since_last_delay_estimate_ = 300000;
-  int echo_path_delay_samples_ = 0;
+  int echo_path_delay_samples_ = kMinEchoPathDelayBlocks * kBlockSize;
   size_t align_call_counter_ = 0;
   rtc::Optional<size_t> headroom_samples_;
   RenderDelayControllerMetrics metrics_;
   RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(RenderDelayControllerImpl);
 };
 
 size_t ComputeNewBufferDelay(size_t current_delay,
                              size_t echo_path_delay_samples) {
   // The below division is not exact and the truncation is intended.
   const int echo_path_delay_blocks = echo_path_delay_samples / kBlockSize;
@@ skipping 19 matching lines @@
           new ApmDataDumper(rtc::AtomicOps::Increment(&instance_count_))),
       delay_estimator_(data_dumper_.get(), config) {
   RTC_DCHECK(ValidFullBandRate(sample_rate_hz));
 }
 
 RenderDelayControllerImpl::~RenderDelayControllerImpl() = default;
 
 void RenderDelayControllerImpl::Reset() {
   delay_ = kMinEchoPathDelayBlocks;
   blocks_since_last_delay_estimate_ = 300000;
-  echo_path_delay_samples_ = 0;

[peah-webrtc, 2017/09/11 12:31:42]

This is a bit of an unrelated change, but since I correct it in the other place
I also add the correction here. This mainly ensures that the reporting of the
echo_path_delay_samples_ after a reset matches how delay_ is set.

+  echo_path_delay_samples_ = delay_ * kBlockSize;
   align_call_counter_ = 0;
   headroom_samples_ = rtc::Optional<size_t>();
 
   delay_estimator_.Reset();
 }
 
 void RenderDelayControllerImpl::SetDelay(size_t render_delay) {
   if (delay_ != render_delay) {
     // If a the delay set does not match the actual delay, reset the delay
     // controller.
@@ skipping 18 matching lines @@
     const size_t new_delay =
         ComputeNewBufferDelay(delay_, echo_path_delay_samples_);
     if (align_call_counter_ > kNumBlocksPerSecond) {
       delay_ = new_delay;
 
       // Update render delay buffer headroom.
       const int headroom = echo_path_delay_samples_ - delay_ * kBlockSize;
       RTC_DCHECK_LE(0, headroom);
       headroom_samples_ = rtc::Optional<size_t>(headroom);
     }
-  } else if (++blocks_since_last_delay_estimate_ > 20 * kNumBlocksPerSecond) {
-    headroom_samples_ = rtc::Optional<size_t>();
   }
 
   metrics_.Update(echo_path_delay_samples, delay_);
 
   data_dumper_->DumpRaw("aec3_render_delay_controller_delay", 1,
                         &echo_path_delay_samples_);
   data_dumper_->DumpRaw("aec3_render_delay_controller_buffer_delay", delay_);
 
   return delay_;
 }
 
 }  // namespace
 
 RenderDelayController* RenderDelayController::Create(
     const AudioProcessing::Config::EchoCanceller3& config,
     int sample_rate_hz) {
   return new RenderDelayControllerImpl(config, sample_rate_hz);
 }
 
 }  // namespace webrtc