Land Recent QUIC Changes.

net/quic/congestion_control/quic_congestion_manager.h

 // Copyright (c) 2012 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.
 //
 // This is the interface from the QuicConnection into the QUIC
 // congestion control code.  It wraps the SendAlgorithmInterface and
 // ReceiveAlgorithmInterface and provides a single interface
 // for consumers.
 
 #ifndef NET_QUIC_CONGESTION_CONTROL_QUIC_CONGESTION_MANAGER_H_
@@ skipping 69 matching lines @@
   virtual void RecordIncomingPacket(QuicByteCount bytes,
                                     QuicPacketSequenceNumber sequence_number,
                                     QuicTime timestamp,
                                     bool revived);
 
   const QuicTime::Delta DefaultRetransmissionTime();
 
   // Returns amount of time for delayed ack timer.
   const QuicTime::Delta DelayedAckTime();
 
+  // Returns the current RTO delay.  |unacked_packet_count| is the number of
+  // currently outstanding packets.  |number_retransmissions| is the number of
+  // sequential retransmission timeouts that have occrued.
   const QuicTime::Delta GetRetransmissionDelay(
       size_t unacked_packets_count,
       size_t number_retransmissions) const;
 
   // Returns the estimated smoothed RTT calculated by the congestion algorithm.
   const QuicTime::Delta SmoothedRtt() const;
 
   // Returns the estimated bandwidth calculated by the congestion algorithm.
   QuicBandwidth BandwidthEstimate() const;
 
   // Returns the size of the current congestion window in bytes.  Note, this is
   // not the *available* window.  Some send algorithms may not use a congestion
   // window and will return 0.
   QuicByteCount GetCongestionWindow() const;
 
   // Sets the value of the current congestion window to |window|.
   void SetCongestionWindow(QuicByteCount window);
 
  private:
   friend class test::QuicConnectionPeer;
   friend class test::QuicCongestionManagerPeer;
   typedef std::map<QuicPacketSequenceNumber, size_t> PendingPacketsMap;
 
-  // Get the current(last) rtt. Infinite is returned if invalid.
-  const QuicTime::Delta rtt();
-
   void CleanupPacketHistory();
 
   const QuicClock* clock_;
   scoped_ptr<ReceiveAlgorithmInterface> receive_algorithm_;
   scoped_ptr<SendAlgorithmInterface> send_algorithm_;
   SendAlgorithmInterface::SentPacketsMap packet_history_map_;
   PendingPacketsMap pending_packets_;
   QuicPacketSequenceNumber largest_missing_;
-  QuicTime::Delta current_rtt_;
+  QuicTime::Delta rtt_sample_;  // RTT estimate from the most recent ACK.
 
   DISALLOW_COPY_AND_ASSIGN(QuicCongestionManager);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_CONGESTION_CONTROL_QUIC_CONGESTION_MANAGER_H_