net: remove UsingTCPFastOpen() method from StreamSocket class

net/socket/tcp_client_socket.cc

Index: net/socket/tcp_client_socket.cc
diff --git a/net/socket/tcp_client_socket.cc b/net/socket/tcp_client_socket.cc
index d52f08c4166362cbbb4b51139e54c3c65b59d1f5..56238ba0d12cb5412df6fc317770ea9aa561fe24 100644
--- a/net/socket/tcp_client_socket.cc
+++ b/net/socket/tcp_client_socket.cc
@@ -239,10 +239,6 @@ bool TCPClientSocket::WasEverUsed() const {
   return use_history_.was_used_to_convey_data();
 }
 
-bool TCPClientSocket::UsingTCPFastOpen() const {
-  return socket_->UsingTCPFastOpen();
-}
-
 void TCPClientSocket::EnableTCPFastOpenIfSupported() {
   socket_->EnableTCPFastOpenIfSupported();
 }