Added a new echo likelihood stat that reports the maximum value from a previous time period.

webrtc/modules/audio_processing/echo_detector/likelihood_aggregator.cc

+/*
+ *  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.
+ */
+
+#include "webrtc/modules/audio_processing/echo_detector/likelihood_aggregator.h"
+
+#include <algorithm>
+
+#include "webrtc/base/checks.h"
+
+namespace webrtc {
+
+LikelihoodAggregator::LikelihoodAggregator(size_t window_size)
+    : recent_values_(window_size) {
+  RTC_DCHECK_GT(window_size, 0);
+}
+
+LikelihoodAggregator::~LikelihoodAggregator() {}
+
+void LikelihoodAggregator::Update(float value) {
+  recent_values_[insertion_index_] = value;
+  insertion_index_++;
+  insertion_index_ %= recent_values_.size();
+}
+
+float LikelihoodAggregator::max() const {

[hlundin-webrtc, 2017/01/13 09:06:22]

I think this should be named Max() to reflect that it is not "as cheap as a
getter".

[ivoc, 2017/01/13 12:12:29]

Done.

+  return *std::max_element(recent_values_.begin(), recent_values_.end());
+}
+
+void LikelihoodAggregator::Clear() {
+  std::fill(recent_values_.begin(), recent_values_.end(), 0.f);
+}
+
+}  // namespace webrtc