Fixes from polymer.dart API review

samples/third_party/todomvc/test/listorder_test.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 todomvc.test.listorder_test;
 
+import 'dart:async';
 import 'dart:html';
 import 'package:polymer/polymer.dart';
-import 'package:polymer/platform.dart' show endOfMicrotask;
 import 'package:unittest/unittest.dart';
 import 'package:unittest/html_config.dart';
 import '../web/model.dart';
 
 /**
  * This test runs the TodoMVC app, adds a few elements, marks some as done, and
  * switches from back and forth between "Active" and "All". This will make some
  * nodes to be hidden and readded to the page.
  */
 main() {
   initPolymer();
   useHtmlConfiguration();
 
   ShadowRoot root;
 
   setUp(() => Polymer.onReady.then((_) {
     root = query('todo-app').shadowRoot;
   }));
 
   test('programmatically add items to model', () {
     appModel.todos.addAll([
       new Todo('one (unchecked)'),
       new Todo('two (checked)')..done = true,
       new Todo('three (unchecked)')
     ]);
-    endOfMicrotask(expectAsync0(() {
+    Observable.dirtyCheck();
+    return window.animationFrame.then((_) {

[Jennifer Messerly, 2013/10/25 21:02:21]

one idea here is to use mutation observers to watch for expansion.

       expect(root.queryAll('#todo-list li[is=todo-row]').length, 3);
 
       // TODO(jmesserly): HTML Imports breaks relative hash links when the
       // component is at a different path from the main HTML document. For now
       // fix it programmatically.
       for (var a in root.queryAll('#filters > li > a')) {
         a.href = '#${Uri.parse(a.href).fragment}';
       }
-    }));
+    });
   });
 
   test('navigate to #/active', () {
     windowLocation.hash = '#/active';
-    endOfMicrotask(expectAsync0(() {
+    return window.animationFrame.then((_) {
       expect(root.queryAll('#todo-list li[is=todo-row]').length, 2);
-    }));
+    });
   });
 
   test('navigate to #/completed', () {
     windowLocation.hash = '#/completed';
-    endOfMicrotask(expectAsync0(() {
+    return window.animationFrame.then((_) {
       expect(root.queryAll('#todo-list li[is=todo-row]').length, 1);
-    }));
+    });
   });
 
   test('navigate back to #/', () {
     windowLocation.hash = '#/';
-    endOfMicrotask(expectAsync0(() {
+    return window.animationFrame.then((_) {
       expect(root.queryAll('#todo-list li[is=todo-row]').length, 3);
-    }));
+    });
   });
 }