Simplify RTO interaction between the QUIC sent packet manager and the

net/quic/congestion_control/pacing_sender.h

 // 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.
 //
 // A send algorithm which adds pacing on top of an another send algorithm.
 // It uses the underlying sender's bandwidth estimate to determine the
 // pacing rate to be used.  It also takes into consideration the expected
 // resolution of the underlying alarm mechanism to ensure that alarms are
 // not set too aggressively, and to smooth out variations.
 
@@ skipping 29 matching lines @@
   virtual void OnPacketAcked(QuicPacketSequenceNumber acked_sequence_number,
                              QuicByteCount acked_bytes,
                              QuicTime::Delta rtt) OVERRIDE;
   virtual void OnPacketLost(QuicPacketSequenceNumber sequence_number,
                             QuicTime ack_receive_time) OVERRIDE;
   virtual bool OnPacketSent(QuicTime sent_time,
                             QuicPacketSequenceNumber sequence_number,
                             QuicByteCount bytes,
                             TransmissionType transmission_type,
                             HasRetransmittableData is_retransmittable) OVERRIDE;
-  virtual void OnRetransmissionTimeout() OVERRIDE;
+  virtual void OnRetransmissionTimeout(bool packets_retransmitted) OVERRIDE;
   virtual void OnPacketAbandoned(QuicPacketSequenceNumber sequence_number,
                                  QuicByteCount abandoned_bytes) OVERRIDE;
   virtual QuicTime::Delta TimeUntilSend(
       QuicTime now,
       TransmissionType transmission_type,
       HasRetransmittableData has_retransmittable_data,
       IsHandshake handshake) OVERRIDE;
   virtual QuicBandwidth BandwidthEstimate() const OVERRIDE;
   virtual QuicTime::Delta SmoothedRtt() const OVERRIDE;
   virtual QuicTime::Delta RetransmissionDelay() const OVERRIDE;
   virtual QuicByteCount GetCongestionWindow() const OVERRIDE;
 
  private:
   QuicTime::Delta GetTransferTime(QuicByteCount bytes);
 
   scoped_ptr<SendAlgorithmInterface> sender_;  // Underlying sender.
   QuicTime::Delta alarm_granularity_;
   QuicTime next_packet_send_time_;  // When can the next packet be sent.
   bool was_last_send_delayed_;  // True when the last send was delayed.
   QuicByteCount max_segment_size_;
 
   DISALLOW_COPY_AND_ASSIGN(PacingSender);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_CONGESTION_CONTROL_PACING_SENDER_H_