Introduce boot.js: this finally makes it possible to load and run Todomvc

example/todomvc/web/editable_label.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 editable_label;
 
 import 'dart:html';
-import 'package:observe/observe.dart';
+import 'dart:async';
 import 'package:polymer/polymer.dart';
 
 /**
  * Label whose [value] can be edited by double clicking. When editing, it
  * displays a form and input element, otherwise it displays the label.
  */
+@CustomTag('editable-label')
 class EditableLabel extends PolymerElement with ObservableMixin {
   @observable bool editing = false;
   @observable String value = '';
   bool get applyAuthorStyles => true;
 
   // TODO(jmesserly): replace this with allowing not-operator in templates.
   bool get notEditing => !editing;
 
   InputElement get _editBox => getShadowRoot("editable-label").query('#edit');
 
   void created() {
     super.created();
 
     bindProperty(this, const Symbol('editing'),
         () => notifyProperty(this, const Symbol('notEditing')));
   }
 
   void edit() {
     editing = true;
 
     // This causes _editBox to be inserted.
-    deliverChangeRecords();
+    Observable.dirtyCheck();
 
-    // For IE and Firefox: use .focus(), then reset the value to move the
-    // cursor to the end.
-    _editBox.focus();
-    _editBox.value = '';
-    _editBox.value = value;
+    // TODO(sigmund): remove the 2 runAsync calls. To do so, we might want to
+    // make dirtyCheck return a future or something to indicate that all
+    // change propagations are done.
+    runAsync(() => runAsync(() {
+      // For IE and Firefox: use .focus(), then reset the value to move the
+      // cursor to the end.
+      _editBox.focus();
+      _editBox.value = '';
+      _editBox.value = value;
+    }));
   }
 
   void update(Event e) {
     e.preventDefault(); // don't submit the form
     if (!editing) return; // bail if user canceled
     value = _editBox.value;
     editing = false;
   }
 
   void maybeCancel(KeyboardEvent e) {
     if (e.keyCode == KeyCode.ESC) {
       editing = false;
     }
   }
 }