Verify the locale when initializing dates over http

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 d36ac2b3a31eb73d422a64e7135e82fa321d04dd..26bd47688ae1c2484231ef68c40d7639bb9a5986 100644
--- a/pkg/intl/test/date_time_format_http_request_test.dart
+++ b/pkg/intl/test/date_time_format_http_request_test.dart
@@ -11,6 +11,7 @@ library date_time_format_http_request_test;
 
 import 'dart:html';
 import 'package:unittest/html_config.dart';
+import 'package:unittest/unittest.dart';
 import 'package:intl/date_symbol_data_http_request.dart';
 import 'date_time_format_test_stub.dart';
 
@@ -19,5 +20,9 @@ main() {
   var url = "http://localhost:${window.location.port}"
     "/root_dart/pkg/intl/lib/src/data/dates/";
 
+   test("Initializing a locale that needs fallback", () {
+     initializeDateFormatting("de_DE", url).then(expectAsync1((_) => true));
+   });
+
   runWith(smallSetOfLocales, url, initializeDateFormatting);
 }