Reland of net: merge two versions of SetTCPNoDelay() function into one

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 0546e6075a57e7663640ac93993b8fa71f1cd3e4..68229ff68435ba7e077f80122bb95dbf9e0264e2 100644
--- a/net/socket/tcp_socket_posix.cc
+++ b/net/socket/tcp_socket_posix.cc
@@ -43,16 +43,6 @@
 bool g_tcp_fastopen_user_enabled = false;
 // True if TCP FastOpen connect-with-write has failed at least once.
 bool g_tcp_fastopen_has_failed = false;
-
-// SetTCPNoDelay turns on/off buffering in the kernel. By default, TCP sockets
-// will wait up to 200ms for more data to complete a packet before transmitting.
-// After calling this function, the kernel will not wait. See TCP_NODELAY in
-// `man 7 tcp`.
-bool SetTCPNoDelay(int fd, bool no_delay) {
-  int on = no_delay ? 1 : 0;
-  int error = setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &on, sizeof(on));
-  return error == 0;
-}
 
 // SetTCPKeepAlive sets SO_KEEPALIVE.
 bool SetTCPKeepAlive(int fd, bool enable, int delay) {