Fix SecureSocket tests to look up localhost only once, where possible.

tests/standalone/io/secure_client_raw_server_test.dart

Index: tests/standalone/io/secure_client_raw_server_test.dart
diff --git a/tests/standalone/io/secure_client_raw_server_test.dart b/tests/standalone/io/secure_client_raw_server_test.dart
index 9d40baf72981d7a74ca01a7b01ed94c0a2595bd9..e380f753d0494c74ccdb5aed1277549a097d146a 100644
--- a/tests/standalone/io/secure_client_raw_server_test.dart
+++ b/tests/standalone/io/secure_client_raw_server_test.dart
@@ -7,16 +7,16 @@
 // VMOptions=--short_socket_write
 // VMOptions=--short_socket_read --short_socket_write
 
-import "package:expect/expect.dart";
-import "package:path/path.dart";
 import "dart:async";
 import "dart:io";
-import "dart:isolate";
 
-const HOST_NAME = "localhost";
+import "package:async_helper/async_helper.dart";
+import "package:expect/expect.dart";
+
+InternetAddress HOST;
 const CERTIFICATE = "localhost_cert";
 Future<RawSecureServerSocket> startEchoServer() {
-  return RawSecureServerSocket.bind(HOST_NAME,
+  return RawSecureServerSocket.bind(HOST,
                                     0,
                                     CERTIFICATE).then((server) {
     server.listen((RawSecureSocket client) {
@@ -60,7 +60,7 @@ Future<RawSecureServerSocket> startEchoServer() {
 Future testClient(server) {
   Completer success = new Completer();
   List<String> chunks = <String>[];
-  SecureSocket.connect(HOST_NAME, server.port).then((socket) {
+  SecureSocket.connect(HOST, server.port).then((socket) {
     socket.write("Hello server.");
     socket.close();
     socket.listen(
@@ -78,13 +78,13 @@ Future testClient(server) {
 }
 
 void main() {
+  asyncStart();
   String certificateDatabase = Platform.script.resolve('pkcert').toFilePath();
   SecureSocket.initialize(database: certificateDatabase,
                           password: 'dartdart');
-
-  startEchoServer()
+  InternetAddress.lookup("localhost").then((hosts) => HOST = hosts.first)
+      .then((_) => startEchoServer())
       .then(testClient)
-      .then((server) {
-        server.close();
-      });
+      .then((server) => server.close())
+      .then((_) => asyncEnd());
 }