Update to current webrtc library

This is from the upstream library commit id
3326535126e435f1ba647885ce43a8f0f3d317eb, corresponding to Chromium
88.0.4290.1.

webrtc/modules/audio_processing/residual_echo_detector.h

@@ -0,0 +1,90 @@
+/*
+ *  Copyright (c) 2016 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.
+ */
+
+#ifndef MODULES_AUDIO_PROCESSING_RESIDUAL_ECHO_DETECTOR_H_
+#define MODULES_AUDIO_PROCESSING_RESIDUAL_ECHO_DETECTOR_H_
+
+#include <vector>
+
+#include "api/array_view.h"
+#include "modules/audio_processing/echo_detector/circular_buffer.h"
+#include "modules/audio_processing/echo_detector/mean_variance_estimator.h"
+#include "modules/audio_processing/echo_detector/moving_max.h"
+#include "modules/audio_processing/echo_detector/normalized_covariance_estimator.h"
+#include "modules/audio_processing/include/audio_processing.h"
+
+namespace webrtc {
+
+class ApmDataDumper;
+class AudioBuffer;
+
+class ResidualEchoDetector : public EchoDetector {
+ public:
+  ResidualEchoDetector();
+  ~ResidualEchoDetector() override;
+
+  // This function should be called while holding the render lock.
+  void AnalyzeRenderAudio(rtc::ArrayView<const float> render_audio) override;
+
+  // This function should be called while holding the capture lock.
+  void AnalyzeCaptureAudio(rtc::ArrayView<const float> capture_audio) override;
+
+  // This function should be called while holding the capture lock.
+  void Initialize(int capture_sample_rate_hz,
+                  int num_capture_channels,
+                  int render_sample_rate_hz,
+                  int num_render_channels) override;
+
+  // This function is for testing purposes only.
+  void SetReliabilityForTest(float value) { reliability_ = value; }
+
+  // This function should be called while holding the capture lock.
+  EchoDetector::Metrics GetMetrics() const override;
+
+ private:
+  static int instance_count_;
+  std::unique_ptr<ApmDataDumper> data_dumper_;
+  // Keep track if the |Process| function has been previously called.
+  bool first_process_call_ = true;
+  // Buffer for storing the power of incoming farend buffers. This is needed for
+  // cases where calls to BufferFarend and Process are jittery.
+  CircularBuffer render_buffer_;
+  // Count how long ago it was that the size of |render_buffer_| was zero. This
+  // value is also reset to zero when clock drift is detected and a value from
+  // the renderbuffer is discarded, even though the buffer is not actually zero
+  // at that point. This is done to avoid repeatedly removing elements in this
+  // situation.
+  size_t frames_since_zero_buffer_size_ = 0;
+
+  // Circular buffers containing delayed versions of the power, mean and
+  // standard deviation, for calculating the delayed covariance values.
+  std::vector<float> render_power_;
+  std::vector<float> render_power_mean_;
+  std::vector<float> render_power_std_dev_;
+  // Covariance estimates for different delay values.
+  std::vector<NormalizedCovarianceEstimator> covariances_;
+  // Index where next element should be inserted in all of the above circular
+  // buffers.
+  size_t next_insertion_index_ = 0;
+
+  MeanVarianceEstimator render_statistics_;
+  MeanVarianceEstimator capture_statistics_;
+  // Current echo likelihood.
+  float echo_likelihood_ = 0.f;
+  // Reliability of the current likelihood.
+  float reliability_ = 0.f;
+  MovingMax recent_likelihood_max_;
+
+  int log_counter_ = 0;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_PROCESSING_RESIDUAL_ECHO_DETECTOR_H_