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

net/tools/flip_server/tcp_socket_util.h

Index: net/tools/flip_server/tcp_socket_util.h
diff --git a/net/tools/flip_server/tcp_socket_util.h b/net/tools/flip_server/tcp_socket_util.h
index 4e2e910ef431126a3af2380fa573f917ff5ec244..cbd35e7260c6398a040168bcf17b6809f8cc8529 100644
--- a/net/tools/flip_server/tcp_socket_util.h
+++ b/net/tools/flip_server/tcp_socket_util.h
@@ -8,6 +8,14 @@
 #include <string>
 
 namespace net {
+
+// This function disables 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`.
+// This function returns true if it succeeds to set the TCP_NODELAY option,
+// otherwise returns false.
+bool SetTCPNoDelay(int fd);
 
 // Summary:
 //   creates a socket for listening, and bind()s and listen()s it.