net: remove UsingTCPFastOpen() method from StreamSocket class

net/socket/tcp_socket_posix.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_POSIX_H_
 #define NET_SOCKET_TCP_SOCKET_POSIX_H_
 
 #include <stdint.h>
 
 #include "base/callback.h"
@@ skipping 55 matching lines @@
   bool SetKeepAlive(bool enable, int delay);
   bool SetNoDelay(bool no_delay);
 
   // Gets the estimated RTT. Returns false if the RTT is
   // unavailable. May also return false when estimated RTT is 0.
   bool GetEstimatedRoundTripTime(base::TimeDelta* out_rtt) const
       WARN_UNUSED_RESULT;
 
   void Close();
 
-  // Setter/Getter methods for TCP FastOpen socket option.
-  bool UsingTCPFastOpen() const;
   void EnableTCPFastOpenIfSupported();
 
   bool IsValid() const;
 
   // Detachs from the current thread, to allow the socket to be transferred to
   // a new thread. Should only be called when the object is no longer used by
   // the old thread.
   void DetachFromThread();
 
   // Marks the start/end of a series of connect attempts for logging purpose.
@@ skipping 130 matching lines @@
   bool logging_multiple_connect_attempts_;
 
   BoundNetLog net_log_;
 
   DISALLOW_COPY_AND_ASSIGN(TCPSocketPosix);
 };
 
 }  // namespace net
 
 #endif  // NET_SOCKET_TCP_SOCKET_POSIX_H_