Clean up stock_app.dart

sky/framework/components/scaffold.dart

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 import '../fn.dart';
 import 'action_bar.dart';
 import 'drawer.dart';
 import 'floating_action_button.dart';
 import 'package:sky/framework/theme/typography.dart' as typography;
 
@@ skipping 15 matching lines @@
     bottom: 16px;
     right: 16px;''');
 
   static final Style _drawerStyle = new Style('''
     position: absolute;
     top: 0;
     left: 0;
     bottom: 0;
     right: 0;''');
 
-  ActionBar actionBar;
+  Node header;
   Node content;
   FloatingActionButton fab;
   Drawer drawer;
   List<Node> overlays;
 
   Scaffold({
     Object key,
-    this.actionBar,
+    this.header,
     this.content,
     this.fab,
     this.drawer,
     this.overlays
   }) : super(key: key);
 
   Node build() {
-    var children = [
+    List<Node> children = [
       new Container(
         key: 'Main',
         style: _mainStyle,
-        children: [
-          actionBar,
-          new StyleNode(content, _contentStyle)
-        ]
-      ),
+        children: [header, new StyleNode(content, _contentStyle)])
     ];
 
     if (fab != null)
       children.add(new StyleNode(fab, _fabStyle));
 
     if (drawer != null)
       children.add(new StyleNode(drawer, _drawerStyle));
 
     if (overlays != null)
       children.addAll(overlays);
 
     return new Container(style: _style, children: children);
   }
 }