Make TimeWaitListManager use PacketWriter's socket writability state.

net/tools/quic/quic_time_wait_list_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.
 //
 // Handles packets for guids in time wait state by discarding the packet and
 // sending the clients a public reset packet with exponential backoff.
 
 #ifndef NET_TOOLS_QUIC_QUIC_TIME_WAIT_LIST_MANAGER_H_
 #define NET_TOOLS_QUIC_QUIC_TIME_WAIT_LIST_MANAGER_H_
 
@@ skipping 85 matching lines @@
   // Creates a public reset packet and sends it or queues it to be sent later.
   void SendPublicReset(const IPEndPoint& server_address,
                        const IPEndPoint& client_address,
                        QuicGuid guid,
                        QuicPacketSequenceNumber rejected_sequence_number);
 
   // Either sends the packet and deletes it or makes pending_packets_queue_ the
   // owner of the packet.
   void SendOrQueuePacket(QueuedPacket* packet);
 
-  // Should only be called when write_blocked_ == false. We only care if the
-  // writing was unsuccessful because the socket got blocked, which can be
-  // tested using write_blocked_ == true. In case of all other errors we drop
-  // the packet. Hence, we return void.
-  void WriteToWire(QueuedPacket* packet);
+  // Sends the packet out. Returns true if the packet was successfully consumed.
+  // If the writer got blocked and did not buffer the packet, we'll need to keep
+  // the packet and retry sending. In case of all other errors we drop the
+  // packet.
+  bool WriteToWire(QueuedPacket* packet);
 
   // Register the alarm with the epoll server to wake up at appropriate time.
   void SetGuidCleanUpAlarm();
 
   // A map from a recently closed guid to the number of packets received after
   // the termination of the connection bound to the guid.
   struct GuidData {
     GuidData(int num_packets_,
              QuicVersion version_,
              QuicEncryptedPacket* close_packet)
@@ skipping 25 matching lines @@
   // Alarm registered with the epoll server to clean up guids that have out
   // lived their duration in time wait state.
   scoped_ptr<GuidCleanUpAlarm> guid_clean_up_alarm_;
 
   // Clock to efficiently measure approximate time from the epoll server.
   QuicEpollClock clock_;
 
   // Interface that writes given buffer to the socket. Owned by the dispatcher.
   QuicPacketWriter* writer_;
 
-  // True if the underlying udp socket is write blocked, i.e will return EAGAIN
-  // on sendmsg.
-  bool is_write_blocked_;
-
   DISALLOW_COPY_AND_ASSIGN(QuicTimeWaitListManager);
 };
 
 }  // namespace tools
 }  // namespace net
 
 #endif  // NET_TOOLS_QUIC_QUIC_TIME_WAIT_LIST_MANAGER_H_