Along with sending the SCUP message, this CL includes small fixes which

net/quic/quic_sent_packet_manager.h

 // Copyright 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.
 
 #ifndef NET_QUIC_QUIC_SENT_PACKET_MANAGER_H_
 #define NET_QUIC_QUIC_SENT_PACKET_MANAGER_H_
 
 #include <deque>
 #include <list>
 #include <map>
@@ skipping 93 matching lines @@
 
   QuicSentPacketManager(bool is_server,
                         const QuicClock* clock,
                         QuicConnectionStats* stats,
                         CongestionControlType congestion_control_type,
                         LossDetectionType loss_type);
   virtual ~QuicSentPacketManager();
 
   virtual void SetFromConfig(const QuicConfig& config);
 
+  void SetHandshakeConfirmed() { handshake_confirmed_ = true; }
+
   // Called when a new packet is serialized.  If the packet contains
   // retransmittable data, it will be added to the unacked packet map.
   void OnSerializedPacket(const SerializedPacket& serialized_packet);
 
   // Called when a packet is retransmitted with a new sequence number.
   // Replaces the old entry in the unacked packet map with the new
   // sequence number.
   void OnRetransmittedPacket(QuicPacketSequenceNumber old_sequence_number,
                              QuicPacketSequenceNumber new_sequence_number);
 
@@ skipping 231 matching lines @@
   // Whether a tlp packet can be sent even if the send algorithm says not to.
   bool pending_tlp_transmission_;
   // Maximum number of tail loss probes to send before firing an RTO.
   size_t max_tail_loss_probes_;
   bool using_pacing_;
 
   // Sets of packets acked and lost as a result of the last congestion event.
   SendAlgorithmInterface::CongestionMap packets_acked_;
   SendAlgorithmInterface::CongestionMap packets_lost_;
 
+  // Set to true after the crypto handshake has successfully completed. After
+  // this is true we no longer use HANDSHAKE_MODE, and further frames sent on
+  // the crypto stream (i.e. SCUP messages) are treated like normal
+  // retransmittable frames.
+  bool handshake_confirmed_;
+
   DISALLOW_COPY_AND_ASSIGN(QuicSentPacketManager);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_QUIC_SENT_PACKET_MANAGER_H_