Add average rtt to CallStatsObserver and an average rtt histogram.

webrtc/video_engine/vie_channel.h

 /*
  *  Copyright (c) 2012 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 298 matching lines @@
   void RegisterRtcpPacketTypeCounterObserver(
       RtcpPacketTypeCounterObserver* observer);
   void RegisterReceiveStatisticsProxy(
       ReceiveStatisticsProxy* receive_statistics_proxy);
   void SetIncomingVideoStream(IncomingVideoStream* incoming_video_stream);
 
  protected:
   static bool ChannelDecodeThreadFunction(void* obj);
   bool ChannelDecodeProcess();
 
-  void OnRttUpdate(int64_t rtt);
+  void OnRttUpdate(int64_t avg_rtt_ms, int64_t max_rtt_ms);
 
   int ProtectionRequest(const FecProtectionParams* delta_fec_params,
                         const FecProtectionParams* key_fec_params,
                         uint32_t* sent_video_rate_bps,
                         uint32_t* sent_nack_rate_bps,
                         uint32_t* sent_fec_rate_bps);
 
  private:
   static std::vector<RtpRtcp*> CreateRtpRtcpModules(
       int32_t id,
@@ skipping 146 matching lines @@
   // Current receive codec used for codec change callback.
   VideoCodec receive_codec_ GUARDED_BY(crit_);
   rtc::scoped_ptr<ThreadWrapper> decode_thread_;
 
   int nack_history_size_sender_;
   int max_nack_reordering_threshold_;
   I420FrameCallback* pre_render_callback_ GUARDED_BY(crit_);
 
   const rtc::scoped_ptr<ReportBlockStats> report_block_stats_sender_;
 
+  int64_t time_of_first_rtt_ms_ GUARDED_BY(crit_);
+  int64_t rtt_sum_ms_ GUARDED_BY(crit_);
+  size_t num_rtts_ GUARDED_BY(crit_);
+
   // RtpRtcp modules, declared last as they use other members on construction.
   const std::vector<RtpRtcp*> rtp_rtcp_modules_;
   size_t num_active_rtp_rtcp_modules_ GUARDED_BY(crit_);
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_VIDEO_ENGINE_VIE_CHANNEL_H_