Async initialization for DateFormat

pkg/intl/test/date_time_format_file_test.dart

+// Copyright (c) 2012, 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.
+
+/**
+ * Tests date formatting and parsing using locale data read from the
+ * local file system.
+ */
+
+#library('date_time_format_test');
+
+#import('../date_format.dart');
+#import('../date_symbol_data_file.dart');
+#import('dart:io');
+#import('date_time_format_test_core.dart');
+#import('data_directory.dart');
+
+main() {
+  // Initialize one locale just so we know what the list is.
+  initializeDateFormatting("en_US", dataDirectory).then(runEverything);
+}
+
+void runEverything(_) {
+  // Initialize all locales and wait for them to finish before running tests.
+  var futures = DateFormat.allLocalesWithSymbols().map(
+      (locale) => initializeDateFormatting(locale, dataDirectory));
+  Futures.wait(futures).then((results) => runDateTests());
+}