Make TCPClientSocket* inherit from NonThreadSafe.

net/socket/tcp_client_socket_libevent.h

 // Copyright (c) 2010 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_SOCKET_TCP_CLIENT_SOCKET_LIBEVENT_H_
 #define NET_SOCKET_TCP_CLIENT_SOCKET_LIBEVENT_H_
 
 #include "base/message_loop.h"
+#include "base/non_thread_safe.h"
 #include "base/ref_counted.h"
 #include "base/scoped_ptr.h"
 #include "net/base/address_list.h"
 #include "net/base/completion_callback.h"
 #include "net/base/net_log.h"
 #include "net/socket/client_socket.h"
 
 struct event;  // From libevent
 
 namespace net {
 
 class BoundNetLog;
 
 // A client socket that uses TCP as the transport layer.
-class TCPClientSocketLibevent : public ClientSocket {
+class TCPClientSocketLibevent : public ClientSocket, NonThreadSafe {
  public:
   // The IP address(es) and port number to connect to.  The TCP socket will try
   // each IP address in the list until it succeeds in establishing a
   // connection.
   explicit TCPClientSocketLibevent(const AddressList& addresses,
                                    net::NetLog* net_log);
 
   virtual ~TCPClientSocketLibevent();
 
   // ClientSocket methods:
@@ skipping 99 matching lines @@
   CompletionCallback* write_callback_;
 
   BoundNetLog net_log_;
 
   DISALLOW_COPY_AND_ASSIGN(TCPClientSocketLibevent);
 };
 
 }  // namespace net
 
 #endif  // NET_SOCKET_TCP_CLIENT_SOCKET_LIBEVENT_H_