Port sky_home to the new SkyView world

sky/examples/rendering/touch_demo.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 'dart:math';
 import 'dart:sky';
 
 import 'package:sky/framework/app.dart';
 import 'package:sky/framework/rendering/box.dart';
 import 'package:sky/framework/rendering/object.dart';
@@ skipping 70 matching lines @@
 
 void main() {
   var para = new RenderParagraph(text: "Touch me!");
   var stack = new RenderStack(children: [
     new RenderTouchDemo(),
     para,
   ]);
   // Make the paragraph not fill the whole screen so it doesn't eat events.
   para.parentData..top = 40.0
                  ..left = 20.0;
-  app = new AppView(stack);
+  app = new AppView(root: stack);
 }