Improve computational performance of BWE by switching list to deque.

webrtc/modules/congestion_controller/trendline_estimator.h

 /*
  *  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 WEBRTC_MODULES_CONGESTION_CONTROLLER_TRENDLINE_ESTIMATOR_H_
 #define WEBRTC_MODULES_CONGESTION_CONTROLLER_TRENDLINE_ESTIMATOR_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
-#include <list>
+#include <deque>
 #include <utility>
 
 #include "webrtc/base/constructormagic.h"
 
 namespace webrtc {
 
 class TrendlineEstimator {
  public:
   // |window_size| is the number of points required to compute a trend line.
   // |smoothing_coef| controls how much we smooth out the delay before fitting
@@ skipping 27 matching lines @@
   const double smoothing_coef_;
   const double threshold_gain_;
   // Used by the existing threshold.
   unsigned int num_of_deltas_;
   // Keep the arrival times small by using the change from the first packet.
   int64_t first_arrival_time_ms;
   // Exponential backoff filtering.
   double accumulated_delay_;
   double smoothed_delay_;
   // Linear least squares regression.
-  std::list<std::pair<double, double>> delay_hist_;
+  std::deque<std::pair<double, double>> delay_hist_;
   double trendline_;
 
   RTC_DISALLOW_COPY_AND_ASSIGN(TrendlineEstimator);
 };
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_CONGESTION_CONTROLLER_TRENDLINE_ESTIMATOR_H_