Port sky_home to the new SkyView world

sky/examples/rendering/spinning_flex.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:sky' as sky;
 import 'dart:math' as math;
 import 'package:vector_math/vector_math.dart';
 import 'package:sky/framework/app.dart';
 import 'package:sky/framework/rendering/box.dart';
 import 'package:sky/framework/rendering/flex.dart';
@@ skipping 14 matching lines @@
   }
 
   addFlexChildSolidColor(flexRoot, const sky.Color(0xFFFF00FF), flex: 1);
   addFlexChildSolidColor(flexRoot, const sky.Color(0xFFFFFF00), flex: 2);
   addFlexChildSolidColor(flexRoot, const sky.Color(0xFF00FFFF), flex: 1);
 
   transformBox = new RenderTransform(child: flexRoot, transform: new Matrix4.identity());
 
   RenderPadding root = new RenderPadding(padding: new EdgeDims.all(20.0), child: transformBox);
 
-  app = new AppView(root);
+  app = new AppView(root: root);
 
   addPersistentFrameCallback(rotate);
 }
 
 void rotate(double timeStamp) {
   if (timeBase == null)
     timeBase = timeStamp;
   double delta = (timeStamp - timeBase) / 1000; // radians
 
   transformBox.setIdentity();
   transformBox.translate(transformBox.size.width / 2.0, transformBox.size.height / 2.0);
   transformBox.rotateZ(delta);
   transformBox.translate(-transformBox.size.width / 2.0, -transformBox.size.height / 2.0);
 }