POSIX only: Move client socket functionality from TCPClientSocket into TCPSocket.

net/socket/tcp_socket.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_SOCKET_TCP_SOCKET_H_
 #define NET_SOCKET_TCP_SOCKET_H_
 
 #include "build/build_config.h"
+#include "net/base/net_export.h"
 
 #if defined(OS_WIN)
 #include "net/socket/tcp_socket_win.h"
 #elif defined(OS_POSIX)
 #include "net/socket/tcp_socket_libevent.h"
 #endif
 
 namespace net {
 
+// Enable/disable experimental TCP FastOpen option.
+// Not thread safe.  Must be called during initialization/startup only.
+NET_EXPORT void SetTCPFastOpenEnabled(bool value);
+
+// Check if the TCP FastOpen option is enabled.
+bool IsTCPFastOpenEnabled();
+
 // TCPSocket provides a platform-independent interface for TCP sockets.
 //
 // It is recommended to use TCPClientSocket/TCPServerSocket instead of this
 // class, unless a clear separation of client and server socket functionality is
 // not suitable for your use case (e.g., a socket needs to be created and bound
 // before you know whether it is a client or server socket).
 #if defined(OS_WIN)
 typedef TCPSocketWin TCPSocket;
 #elif defined(OS_POSIX)
 typedef TCPSocketLibevent TCPSocket;
 #endif
 
 }  // namespace net
 
 #endif  // NET_SOCKET_TCP_SOCKET_H_