Allow binding the vm service to IPv6 addresses.

runtime/observatory/tests/service/auth_token_test.dart

Index: runtime/observatory/tests/service/auth_token_test.dart
diff --git a/runtime/observatory/tests/service/auth_token_test.dart b/runtime/observatory/tests/service/auth_token_test.dart
index 6d38fcaa310dd89577af4ee17985b72134f304f0..69c162b44a0f9ea5474392941755fdd288c25138 100644
--- a/runtime/observatory/tests/service/auth_token_test.dart
+++ b/runtime/observatory/tests/service/auth_token_test.dart
@@ -24,7 +24,7 @@ Future<Null> testeeBefore() async {
   // Try connecting to the server without the auth token, it should throw
   // an exception.
   var port = info.serverUri.port;
-  var url = Uri.parse('http://127.0.0.1:$port');
+  var url = Uri.parse('http://localhost:$port');
   var httpClient = new io.HttpClient();
   try {
     var request = await httpClient.getUrl(url);