Update from https://crrev.com/303153

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 23 matching lines @@
 
   // 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;
-
-  // Returns the min_rtt for the entire connection if a min has been measured.
-  // This returns an initial non-zero RTT estimate if no measurements have yet
-  // been made.
-  QuicTime::Delta MinRtt() const;
+  // Returns the EWMA smoothed RTT for the connection.
+  // May return Zero if no valid updates have occurred.
+  QuicTime::Delta smoothed_rtt() const {
+    return smoothed_rtt_;
+  }
 
   int64 initial_rtt_us() const {
     return initial_rtt_us_;
   }
 
   // Sets an initial RTT to be used for SmoothedRtt before any RTT updates.
   void set_initial_rtt_us(int64 initial_rtt_us) {
     initial_rtt_us_ = initial_rtt_us;
   }
 
+  // The most recent rtt measurement.
+  // May return Zero if no valid updates have occurred.
   QuicTime::Delta latest_rtt() const {
     return latest_rtt_;
   }
 
+  // Returns the min_rtt for the entire connection.
+  // May return Zero if no valid updates have occurred.
+  QuicTime::Delta min_rtt() const {
+    return min_rtt_;
+  }
+
   // Returns the min_rtt since SampleNewRecentMinRtt has been called, or the
   // min_rtt for the entire connection if SampleNewMinRtt was never called.
   QuicTime::Delta recent_min_rtt() const {
     return recent_min_rtt_.rtt;
   }
 
   QuicTime::Delta mean_deviation() const {
     return mean_deviation_;
   }
 
@@ skipping 34 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_