Refactor of QUIC's rtt storage and calculation to have a single RttStats

net/quic/congestion_control/send_algorithm_interface.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.
 //
 // The pure virtual class for send side congestion control algorithm.
 
 #ifndef NET_QUIC_CONGESTION_CONTROL_SEND_ALGORITHM_INTERFACE_H_
 #define NET_QUIC_CONGESTION_CONTROL_SEND_ALGORITHM_INTERFACE_H_
 
 #include <algorithm>
 #include <map>
 
 #include "base/basictypes.h"
 #include "net/base/net_export.h"
 #include "net/quic/quic_bandwidth.h"
 #include "net/quic/quic_clock.h"
 #include "net/quic/quic_config.h"
 #include "net/quic/quic_connection_stats.h"
 #include "net/quic/quic_protocol.h"
 #include "net/quic/quic_time.h"
 
 namespace net {
 
+class RttStats;
+
 class NET_EXPORT_PRIVATE SendAlgorithmInterface {
  public:
   static SendAlgorithmInterface* Create(const QuicClock* clock,
+                                        const RttStats* rtt_stats,
                                         CongestionFeedbackType type,
                                         QuicConnectionStats* stats);
 
   virtual ~SendAlgorithmInterface() {}
 
   virtual void SetFromConfig(const QuicConfig& config, bool is_server) = 0;
 
   // Called when we receive congestion feedback from remote peer.
   virtual void OnIncomingQuicCongestionFeedbackFrame(
       const QuicCongestionFeedbackFrame& feedback,
@@ skipping 32 matching lines @@
       QuicTime now,
       TransmissionType transmission_type,
       HasRetransmittableData has_retransmittable_data,
       IsHandshake handshake) = 0;
 
   // What's the current estimated bandwidth in bytes per second.
   // Returns 0 when it does not have an estimate.
   virtual QuicBandwidth BandwidthEstimate() const = 0;
 
   // Updates the smoothed RTT based on a new sample.
+  // TODO(ianswett): Now that the RTT is managed by RTTStats, it may be
+  // possible to remove this method.
   virtual void UpdateRtt(QuicTime::Delta rtt_sample) = 0;
 
-  // TODO(satyamshekhar): Monitor MinRtt.
-  virtual QuicTime::Delta SmoothedRtt() const = 0;
-
   // Get the send algorithm specific retransmission delay, called RTO in TCP,
   // Note 1: the caller is responsible for sanity checking this value.
   // Note 2: this will return zero if we don't have enough data for an estimate.
   virtual QuicTime::Delta RetransmissionDelay() const = 0;
 
   // 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.
   virtual QuicByteCount GetCongestionWindow() const = 0;
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_CONGESTION_CONTROL_SEND_ALGORITHM_INTERFACE_H_