net: remove UsingTCPFastOpen() method from StreamSocket class

net/socket/unix_domain_client_socket_posix.cc

 // Copyright 2014 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.
 
 #include "net/socket/unix_domain_client_socket_posix.h"
 
 #include <sys/socket.h>
 #include <sys/un.h>
 #include <utility>
 
@@ skipping 113 matching lines @@
 void UnixDomainClientSocket::SetSubresourceSpeculation() {
 }
 
 void UnixDomainClientSocket::SetOmniboxSpeculation() {
 }
 
 bool UnixDomainClientSocket::WasEverUsed() const {
   return true;  // We don't care.
 }
 
-bool UnixDomainClientSocket::UsingTCPFastOpen() const {
-  return false;
-}
-
 bool UnixDomainClientSocket::WasNpnNegotiated() const {
   return false;
 }
 
 NextProto UnixDomainClientSocket::GetNegotiatedProtocol() const {
   return kProtoUnknown;
 }
 
 bool UnixDomainClientSocket::GetSSLInfo(SSLInfo* ssl_info) {
   return false;
@@ skipping 34 matching lines @@
 SocketDescriptor UnixDomainClientSocket::ReleaseConnectedSocket() {
   DCHECK(socket_);
   DCHECK(socket_->IsConnected());
 
   SocketDescriptor socket_fd = socket_->ReleaseConnectedSocket();
   socket_.reset();
   return socket_fd;
 }
 
 }  // namespace net