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

tests/standalone/io/raw_secure_server_closing_test.dart

 // 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.
 //
 // VMOptions=
 // VMOptions=--short_socket_read
 // VMOptions=--short_socket_write
 // VMOptions=--short_socket_read --short_socket_write
 
 import "dart:async";
 import "dart:io";
 
 import "package:async_helper/async_helper.dart";
 import "package:expect/expect.dart";
-import "package:path/path.dart";
 
-const HOST_NAME = "localhost";
+InternetAddress HOST;
 const CERTIFICATE = "localhost_cert";
 
 void testCloseOneEnd(String toClose) {
   asyncStart();
   Completer serverDone = new Completer();
   Completer serverEndDone = new Completer();
   Completer clientEndDone = new Completer();
   Future.wait([serverDone.future, serverEndDone.future, clientEndDone.future])
       .then((_) {
         asyncEnd();
       });
-  RawSecureServerSocket.bind(HOST_NAME, 0, CERTIFICATE).then((server) {
+  RawSecureServerSocket.bind(HOST, 0, CERTIFICATE).then((server) {
     server.listen((serverConnection) {
       serverConnection.listen((event) {
         if (toClose == "server" || event == RawSocketEvent.READ_CLOSED) {
           serverConnection.shutdown(SocketDirection.SEND);
         }
       },
       onDone: () {
         serverEndDone.complete(null);
       });
     },
     onDone: () {
       serverDone.complete(null);
     });
-    RawSecureSocket.connect(HOST_NAME, server.port).then((clientConnection) {
+    RawSecureSocket.connect(HOST, server.port).then((clientConnection) {
       clientConnection.listen((event){
         if (toClose == "client" || event == RawSocketEvent.READ_CLOSED) {
           clientConnection.shutdown(SocketDirection.SEND);
         }
       },
       onDone: () {
         clientEndDone.complete(null);
         server.close();
       });
     });
   });
 }
 
 void testCloseBothEnds() {
   asyncStart();
-  RawSecureServerSocket.bind(HOST_NAME, 0, CERTIFICATE).then((server) {
-    var clientEndFuture = RawSecureSocket.connect(HOST_NAME, server.port);
+  RawSecureServerSocket.bind(HOST, 0, CERTIFICATE).then((server) {
+    var clientEndFuture = RawSecureSocket.connect(HOST, server.port);
     server.listen((serverEnd) {
       clientEndFuture.then((clientEnd) {
         clientEnd.close();
         serverEnd.close();
         server.close();
         asyncEnd();
       });
     });
   });
 }
 
 testPauseServerSocket() {
   const int socketCount = 10;
   var acceptCount = 0;
   var resumed = false;
 
   asyncStart();
 
-  RawSecureServerSocket.bind(HOST_NAME,
+  RawSecureServerSocket.bind(HOST,
                              0,
                              CERTIFICATE,
                              backlog: 2 * socketCount).then((server) {
     Expect.isTrue(server.port > 0);
     var subscription;
     subscription = server.listen((connection) {
       Expect.isTrue(resumed);
       connection.shutdown(SocketDirection.SEND);
       if (++acceptCount == 2 * socketCount) {
         server.close();
         asyncEnd();
       }
     });
 
     // Pause the server socket subscription and resume it after having
     // connected a number client sockets. Then connect more client
     // sockets.
     subscription.pause();
     var connectCount = 0;
     for (int i = 0; i < socketCount; i++) {
-      RawSecureSocket.connect(HOST_NAME, server.port).then((connection) {
+      RawSecureSocket.connect(HOST, server.port).then((connection) {
         connection.shutdown(SocketDirection.SEND);
       });
     }
     new Timer(const Duration(milliseconds: 500), () {
       subscription.resume();
       resumed = true;
       for (int i = 0; i < socketCount; i++) {
-        RawSecureSocket.connect(HOST_NAME, server.port).then((connection) {
+        RawSecureSocket.connect(HOST, server.port).then((connection) {
           connection.shutdown(SocketDirection.SEND);
         });
       }
     });
   });
 }
 
 testCloseServer() {
   const int socketCount = 3;
   asyncStart();
   List ends = [];
 
-  RawSecureServerSocket.bind(HOST_NAME, 0, CERTIFICATE).then((server) {
+  RawSecureServerSocket.bind(HOST, 0, CERTIFICATE).then((server) {
     Expect.isTrue(server.port > 0);
     void checkDone() {
       if (ends.length < 2 * socketCount) return;
       for (var end in ends) {
         end.close();
       }
       server.close();
       asyncEnd();
     }
 
     server.listen((connection) {
       ends.add(connection);
       checkDone();
     });
 
     for (int i = 0; i < socketCount; i++) {
-      RawSecureSocket.connect(HOST_NAME, server.port).then((connection) {
+      RawSecureSocket.connect(HOST, server.port).then((connection) {
         ends.add(connection);
         checkDone();
       });
     }
   });
 }
 
 
 main() {
+  asyncStart();
   var certificateDatabase = Platform.script.resolve('pkcert').toFilePath();
   SecureSocket.initialize(database: certificateDatabase,
                           password: 'dartdart',
                           useBuiltinRoots: false);
+  InternetAddress.lookup("localhost").then((hosts) {
+    HOST = hosts.first;
+    runTests();
+    asyncEnd();
+  });
+}
 
+runTests() {
   testCloseOneEnd("client");
   testCloseOneEnd("server");
   testCloseBothEnds();
   testCloseServer();
   testPauseServerSocket();
   // TODO(whesse): Add testPauseSocket from raw_socket_test.dart.
   // TODO(whesse): Add testCancelResubscribeSocket from raw_socket_test.dart.
 }