Adding Angular and dependent packages for testing

third_party/pkg/route_hierarchical/lib/src/async_utils.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.
+
+library route.async_utils;
+
+import 'dart:async';
+
+Future doWhile(Iterable iterable, Future<bool> action(i)) =>
+    _doWhile(iterable.iterator, action);
+
+Future _doWhile(Iterator iterator, Future<bool> action(i)) =>
+  (iterator.moveNext())
+      ? action(iterator.current).then((bool result) =>
+        (result)
+            ? _doWhile(iterator, action)
+            : new Future.value(false))
+      : new Future.value(false);