Fix theme changing: turns out we were not reparenting stateful surviving nodes when their parents c…

sky/sdk/example/stocks/lib/main.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/rendering/sky_binding.dart';
 import 'package:sky/theme/colors.dart' as colors;
 import 'package:sky/theme/theme_data.dart';
 import 'package:sky/widgets/basic.dart';
 import 'package:sky/widgets/navigator.dart';
 import 'package:sky/widgets/theme.dart';
@@ skipping 43 matching lines @@
   final List<Stock> _stocks = [];
   void didMount() {
     super.didMount();
     new StockDataFetcher((StockData data) {
       setState(() {
         data.appendTo(_stocks);
       });
     });
   }
 
-  Widget build() {
-    return new Theme(
-      data: new ThemeData.light(
+   Widget build() {
+
+    ThemeData theme;
+    if (stockMode == StockMode.optimistic) {
+      theme = new ThemeData.light(
         primary: colors.Purple,
         accent: colors.RedAccent,
-        darkToolbar: true),
-      child: new Navigator(_navigationState)
-    );
-  }
+        darkToolbar: true
+      );
+    } else {
+      theme = new ThemeData.dark(
+        primary: colors.Red,
+        accent: colors.PurpleAccent
+      );
+    }
+
+    return new Theme(
+      data: theme,
+       child: new Navigator(_navigationState)
+     );
+   }
 }
 
 void main() {
   print("starting stocks app!");
-  runApp(new StocksApp());
+  runApp(new StocksApp(), enableProfilingLoop: true);
+  // set enableProfilingLoop to true to make the app rebuild continually every 20ms
   SkyBinding.instance.onFrame = () {
-    // uncomment this for debugging:
+    // uncomment this to print the RenderObject tree every frame:
     // SkyBinding.instance.debugDumpRenderTree();
   };
 }