net: remove UsingTCPFastOpen() method from StreamSocket class

net/socket/ssl_client_socket_nss.cc

Index: net/socket/ssl_client_socket_nss.cc
diff --git a/net/socket/ssl_client_socket_nss.cc b/net/socket/ssl_client_socket_nss.cc
index f1f00d13fca8875c7efa07bbeb85b20537b41c50..027b46ed34330c1ba41e4afca145249d56d17af3 100644
--- a/net/socket/ssl_client_socket_nss.cc
+++ b/net/socket/ssl_client_socket_nss.cc
@@ -2620,14 +2620,6 @@ bool SSLClientSocketNSS::WasEverUsed() const {
   return core_->WasEverUsed();
 }
 
-bool SSLClientSocketNSS::UsingTCPFastOpen() const {
-  if (transport_.get() && transport_->socket()) {
-    return transport_->socket()->UsingTCPFastOpen();
-  }
-  NOTREACHED();
-  return false;
-}
-
 int SSLClientSocketNSS::Read(IOBuffer* buf, int buf_len,
                              const CompletionCallback& callback) {
   DCHECK(core_.get());