net: remove UsingTCPFastOpen() method from StreamSocket class

net/socket/tcp_socket_posix.cc

Index: net/socket/tcp_socket_posix.cc
diff --git a/net/socket/tcp_socket_posix.cc b/net/socket/tcp_socket_posix.cc
index 68229ff68435ba7e077f80122bb95dbf9e0264e2..95fe6b5bd011b8f96f5f8ac321974b0f2ddd0841 100644
--- a/net/socket/tcp_socket_posix.cc
+++ b/net/socket/tcp_socket_posix.cc
@@ -433,10 +433,6 @@ void TCPSocketPosix::Close() {
   tcp_fastopen_status_ = TCP_FASTOPEN_STATUS_UNKNOWN;
 }
 
-bool TCPSocketPosix::UsingTCPFastOpen() const {
-  return use_tcp_fastopen_;
-}
-
 void TCPSocketPosix::EnableTCPFastOpenIfSupported() {
   if (!IsTCPFastOpenSupported())
     return;
@@ -445,7 +441,7 @@ void TCPSocketPosix::EnableTCPFastOpenIfSupported() {
   // This check conservatively avoids middleboxes that may blackhole
   // TCP FastOpen SYN+Data packets; on such a failure, subsequent sockets
   // should not use TCP FastOpen.
-  if(!g_tcp_fastopen_has_failed)
+  if (!g_tcp_fastopen_has_failed)
     use_tcp_fastopen_ = true;
   else
     tcp_fastopen_status_ = TCP_FASTOPEN_PREVIOUSLY_FAILED;