Update RateStatistics to handle too-little-data case.

webrtc/modules/remote_bitrate_estimator/remote_bitrate_estimator_abs_send_time.h

 /*
  *  Copyright (c) 2015 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 106 matching lines @@
       EXCLUSIVE_LOCKS_REQUIRED(&crit_);
 
   void TimeoutStreams(int64_t now_ms) EXCLUSIVE_LOCKS_REQUIRED(&crit_);
 
   rtc::ThreadChecker network_thread_;
   RemoteBitrateObserver* const observer_;
   std::unique_ptr<InterArrival> inter_arrival_;
   std::unique_ptr<OveruseEstimator> estimator_;
   OveruseDetector detector_;
   RateStatistics incoming_bitrate_;
+  bool incoming_bitrate_initialized_;
   std::vector<int> recent_propagation_delta_ms_;
   std::vector<int64_t> recent_update_time_ms_;
   std::list<Probe> probes_;
   size_t total_probes_received_;
   int64_t first_packet_time_ms_;
   int64_t last_update_ms_;
 
   rtc::CriticalSection crit_;
   Ssrcs ssrcs_ GUARDED_BY(&crit_);
   AimdRateControl remote_rate_ GUARDED_BY(&crit_);
 
   RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(RemoteBitrateEstimatorAbsSendTime);
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_REMOTE_BITRATE_ESTIMATOR_REMOTE_BITRATE_ESTIMATOR_ABS_SEND_TIME_H_