Add cross-origin test with credentials.

pkg/intl/test/date_time_format_http_request_test.dart

Index: pkg/intl/test/date_time_format_http_request_test.dart
diff --git a/pkg/intl/test/date_time_format_http_request_test.dart b/pkg/intl/test/date_time_format_http_request_test.dart
index fb147b44097fc1f2bb7a777219bac7e9ea285275..9dcf114f861f0ca25f36e5cc06dc2acca779a1be 100644
--- a/pkg/intl/test/date_time_format_http_request_test.dart
+++ b/pkg/intl/test/date_time_format_http_request_test.dart
@@ -14,10 +14,13 @@ import '../lib/date_symbol_data_http_request.dart';
 import 'date_time_format_test_core.dart';
 import 'dart:html';
 import '../../../pkg/unittest/lib/unittest.dart';
+import '../../../pkg/unittest/lib/html_config.dart';
 
-var url = "http://localhost:9876/pkg/intl/lib/src/data/dates/";
+var url = '';
 
 main() {
+  useHtmlConfiguration();
+  url = "http://localhost:${window.location.port}/pkg/intl/lib/src/data/dates/";
   // Initialize one locale just so we know what the list is.
   test('Run everything', () {
     initializeDateFormatting("en_US", url).then(expectAsync1(runEverything));});
@@ -29,11 +32,5 @@ void runEverything(_) {
       (locale) => initializeDateFormatting(locale, url));
   Futures.wait(futures).then(expectAsync1((_) {
       runDateTests(smallSetOfLocales());
-      shutDown();}));
-}
-
-void shutDown() {
-  // The tiny web server knows to use this request as a cue to terminate.
-  var source = '${url}terminate';
-  var request = new HttpRequest.get(source, (_) {});
+    }));
 }