Port DrawerHeader to fn2 world.

sky/examples/stocks2/lib/stock_app.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 'package:sky/framework/components2/tool_bar.dart';
 import 'package:sky/framework/components2/drawer.dart';
-// import 'package:sky/framework/components2/drawer_header.dart';
+import 'package:sky/framework/components2/drawer_header.dart';
 import 'package:sky/framework/components2/floating_action_button.dart';
 import 'package:sky/framework/components2/icon.dart';
 import 'package:sky/framework/components2/icon_button.dart';
 import 'package:sky/framework/components2/menu_divider.dart';
 import 'package:sky/framework/components2/menu_item.dart';
 import 'package:sky/framework/components2/input.dart';
 // import 'package:sky/framework/components2/modal_overlay.dart';
 // import 'package:sky/framework/components2/popup_menu.dart';
 import 'package:sky/framework/components2/radio.dart';
 import 'package:sky/framework/components2/scaffold.dart';
@@ skipping 90 matching lines @@
     setState(() {
       _stockMode = value;
     });
   }
 
   Drawer buildDrawer() {
     return new Drawer(
       controller: _drawerController,
       level: 3,
       children: [
-        // new DrawerHeader(children: [new Text('Stocks')]),
+        new DrawerHeader(children: [new Text('Stocks')]),
         new MenuItem(
           key: 'Stock list',
           icon: 'action/assessment',
           children: [new Text('Stock List')]),
         new MenuItem(
           key: 'Account Balance',
           icon: 'action/account_balance',
           children: [new Text('Account Balance')]),
         new MenuDivider(key: 'div1'),
         new MenuItem(
@@ skipping 86 matching lines @@
 }
 
 void main() {
   print("starting stocks app!");
   App app = new StocksApp();
   app.appView.onFrame = () {
     // uncomment this for debugging:
     // app.appView.debugDumpRenderTree();
   };
 }