Land Recent QUIC Changes

net/quic/congestion_control/rtt_stats.h

 // Copyright 2014 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.
 //
 // A convenience class to store rtt samples and calculate smoothed rtt.
 
 #ifndef NET_QUIC_CONGESTION_CONTROL_RTT_STATS_H_
 #define NET_QUIC_CONGESTION_CONTROL_RTT_STATS_H_
 
 #include <algorithm>
@@ skipping 14 matching lines @@
 
   // Returns true if any RTT measurements have been made.
   bool HasUpdates() const;
 
   // Updates the RTT from an incoming ack which is received |send_delta| after
   // the packet is sent and the peer reports the ack being delayed |ack_delay|.
   void UpdateRtt(QuicTime::Delta send_delta,
                  QuicTime::Delta ack_delay,
                  QuicTime now);
 
-  // Causes the smoothed_rtt to be increased to the latest_rtt and the
-  // mean_variance to be increased to the most recent variance.
+  // Causes the smoothed_rtt to be increased to the latest_rtt if the latest_rtt
+  // is larger. The mean deviation is increased to the most recent deviation if
+  // it's larger.
   void ExpireSmoothedMetrics();
 
   // Forces RttStats to sample a new recent min rtt within the next
   // |num_samples| UpdateRtt calls.
   void SampleNewRecentMinRtt(uint32 num_samples);
 
   QuicTime::Delta SmoothedRtt() const;
 
   int64 initial_rtt_us() const {
     return initial_rtt_us_;
@@ skipping 60 matching lines @@
   RttSample recent_min_rtt_;  // a in the windowed algorithm.
   RttSample half_window_rtt_;  // b in the sampled algorithm.
   RttSample quarter_window_rtt_;  // c in the sampled algorithm.
 
   DISALLOW_COPY_AND_ASSIGN(RttStats);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_CONGESTION_CONTROL_RTT_STATS_H_