Add setNoDelay method on Socket/RawSocket.

runtime/bin/socket_linux.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "platform/globals.h"
 #if defined(TARGET_OS_LINUX)
 
 #include <errno.h>  // NOLINT
 #include <stdio.h>  // NOLINT
 #include <stdlib.h>  // NOLINT
 #include <string.h>  // NOLINT
 #include <sys/stat.h>  // NOLINT
 #include <unistd.h>  // NOLINT
+#include <netinet/tcp.h>  // NOLINT
 
 #include "bin/fdutils.h"
 #include "bin/file.h"
 #include "bin/log.h"
 #include "bin/socket.h"
 
 
 bool Socket::Initialize() {
   // Nothing to do on Linux.
   return true;
@@ skipping 255 matching lines @@
 
 bool Socket::SetNonBlocking(intptr_t fd) {
   return FDUtils::SetNonBlocking(fd);
 }
 
 
 bool Socket::SetBlocking(intptr_t fd) {
   return FDUtils::SetBlocking(fd);
 }
 
+
+bool Socket::SetNoDelay(intptr_t fd, bool enabled) {
+  int on = enabled ? 1 : 0;
+  return TEMP_FAILURE_RETRY(setsockopt(fd,
+                                       SOL_TCP,
+                                       TCP_NODELAY,
+                                       reinterpret_cast<char *>(&on),
+                                       sizeof(on))) == 0;
+}
+
 #endif  // defined(TARGET_OS_LINUX)