Port of github.com/polymer/polymer.

samples/third_party/todomvc/web/app.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 app;
+library todomvc.web.app;
 
 import 'dart:html';
 import 'package:polymer/polymer.dart';
 import 'model.dart';
 
 @CustomTag("todo-app")
-class TodoApp extends PolymerElement with ObservableMixin {
+class TodoApp extends PolymerElement {
   @observable AppModel app;
   bool get applyAuthorStyles => true;
 
   void created() {
     super.created();
     app = appModel;
   }
 
   void addTodo(Event e) {
     e.preventDefault(); // don't submit the form
     var input = getShadowRoot('todo-app').query('#new-todo');
     if (input.value == '') return;
     app.todos.add(new Todo(input.value));
     input.value = '';
   }
 
   void clear() => app.clearDone();
 }