Allow congestion controller state to be accessed by the debug visitors.

net/quic/core/quic_sent_packet_manager_interface.h

 // Copyright 2016 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.
 
 #ifndef NET_QUIC_QUIC_SENT_PACKET_MANAGER_INTERFACE_H_
 #define NET_QUIC_QUIC_SENT_PACKET_MANAGER_INTERFACE_H_
 
 #include "base/macros.h"
 #include "net/base/net_export.h"
+#include "net/quic/core/congestion_control/send_algorithm_interface.h"
 #include "net/quic/core/quic_packets.h"
 #include "net/quic/core/quic_pending_retransmission.h"
 #include "net/quic/core/quic_sustained_bandwidth_recorder.h"
 
 namespace net {
 
 class QuicConfig;
 class RttStats;
 
 class NET_EXPORT_PRIVATE QuicSentPacketManagerInterface {
@@ skipping 162 matching lines @@
   virtual bool InSlowStart() const = 0;
 
   // These two methods return the consecutive RTO or TLP count of the default
   // path.
   virtual size_t GetConsecutiveRtoCount() const = 0;
   virtual size_t GetConsecutiveTlpCount() const = 0;
 
   // Signals to the congestion controller that the connection has no outstanding
   // data to send.
   virtual void OnApplicationLimited() = 0;
+
+  // Returns the currently used congestion control algorithm.  The manager
+  // retains the ownership of the algorithm.
+  virtual const SendAlgorithmInterface* GetSendAlgorithm() const = 0;
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_QUIC_SENT_PACKET_MANAGER_INTERFACE_H_