Add histograms to record QUIC Min and Smoothed RTT.

net/quic/chromium/quic_connection_logger.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/quic/chromium/quic_connection_logger.h"
 
 #include <algorithm>
 #include <limits>
 #include <memory>
 #include <utility>
@@ skipping 309 matching lines @@
                        num_undecryptable_packets_);
   UMA_HISTOGRAM_COUNTS("Net.QuicSession.DuplicatePacketsReceived",
                        num_duplicate_packets_);
   UMA_HISTOGRAM_COUNTS("Net.QuicSession.BlockedFrames.Received",
                        num_blocked_frames_received_);
   UMA_HISTOGRAM_COUNTS("Net.QuicSession.BlockedFrames.Sent",
                        num_blocked_frames_sent_);
   UMA_HISTOGRAM_COUNTS("Net.QuicSession.HeadersStream.EarlyFramesReceived",
                        session_->headers_stream()->num_early_frames_received());
 
+  const QuicConnectionStats& stats = session_->connection()->GetStats();
+  UMA_HISTOGRAM_TIMES("Net.QuicSession.MinRTT",
+                      base::TimeDelta::FromMicroseconds(stats.min_rtt_us));
+  UMA_HISTOGRAM_TIMES("Net.QuicSession.SmoothedRTT",
+                      base::TimeDelta::FromMicroseconds(stats.srtt_us));
+
   if (num_frames_received_ > 0) {
     int duplicate_stream_frame_per_thousand =
         num_duplicate_frames_received_ * 1000 / num_frames_received_;
     if (num_packets_received_ < 100) {
       UMA_HISTOGRAM_CUSTOM_COUNTS(
           "Net.QuicSession.StreamFrameDuplicatedShortConnection",
           duplicate_stream_frame_per_thousand, 1, 1000, 75);
     } else {
       UMA_HISTOGRAM_CUSTOM_COUNTS(
           "Net.QuicSession.StreamFrameDuplicatedLongConnection",
@@ skipping 504 matching lines @@
       continue;
     }
     // Record some overlapping patterns, to get a better picture, since this is
     // not very expensive.
     if (i % 3 == 0)
       six_packet_histogram->Add(recent_6_mask);
   }
 }
 
 }  // namespace net