net: remove UsingTCPFastOpen() method from StreamSocket class

net/socket/socks5_client_socket.cc

Index: net/socket/socks5_client_socket.cc
diff --git a/net/socket/socks5_client_socket.cc b/net/socket/socks5_client_socket.cc
index bcc4259a93413d1e715eae3f42e9972386f8ab1e..8c172b0b5141c82b87a692bf3bf1d9beeb03ef31 100644
--- a/net/socket/socks5_client_socket.cc
+++ b/net/socket/socks5_client_socket.cc
@@ -113,14 +113,6 @@ bool SOCKS5ClientSocket::WasEverUsed() const {
   return was_ever_used_;
 }
 
-bool SOCKS5ClientSocket::UsingTCPFastOpen() const {
-  if (transport_.get() && transport_->socket()) {
-    return transport_->socket()->UsingTCPFastOpen();
-  }
-  NOTREACHED();
-  return false;
-}
-
 bool SOCKS5ClientSocket::WasNpnNegotiated() const {
   if (transport_.get() && transport_->socket()) {
     return transport_->socket()->WasNpnNegotiated();