Add setNoDelay method on Socket/RawSocket.

sdk/lib/io/http_impl.dart

Index: sdk/lib/io/http_impl.dart
diff --git a/sdk/lib/io/http_impl.dart b/sdk/lib/io/http_impl.dart
index 49071c0e0bb05519516d9b0807c4fac7c65dd24a..ca596c9f8a853bd29a77f5131fa5f27d6bc7ee37 100644
--- a/sdk/lib/io/http_impl.dart
+++ b/sdk/lib/io/http_impl.dart
@@ -1226,6 +1226,7 @@ class _HttpClient implements HttpClient {
                                          sendClientCertificate: true)
                   : Socket.connect(host, port))
         .then((socket) {
+          socket.setOption(SocketOption.TCP_NODELAY, true);
           var connection = new _HttpClientConnection(key, socket, this);
           _activeConnections.add(connection);
           return new _ConnnectionInfo(connection, proxy);
@@ -1388,6 +1389,7 @@ class _HttpServer extends Stream<HttpRequest> implements HttpServer {
                                          bool unsubscribeOnError}) {
     _serverSocket.listen(
         (Socket socket) {
+          socket.setOption(SocketOption.TCP_NODELAY, true);
           // Accept the client connection.
           _HttpConnection connection = new _HttpConnection(socket, this);
           _connections.add(connection);