Give ParentDataNodes snappier names

sky/examples/stocks2/lib/stock_app.dart

Index: sky/examples/stocks2/lib/stock_app.dart
diff --git a/sky/examples/stocks2/lib/stock_app.dart b/sky/examples/stocks2/lib/stock_app.dart
index 6e13b0b4ecc2e5cf2d343ae6dc92b7005ce8fb8b..16b3ce80fc52491bc6dc82130bbc34f24e0c4122 100644
--- a/sky/examples/stocks2/lib/stock_app.dart
+++ b/sky/examples/stocks2/lib/stock_app.dart
@@ -127,7 +127,7 @@ class StocksApp extends App {
           icon: 'action/thumb_up',
           onGestureTap: (event) => _handleStockModeChange(StockMode.optimistic),
           children: [
-            new FlexExpandingChild(new Text('Optimistic'), flex: 1),
+            new Flexible(child: new Text('Optimistic')),
             new Radio(key: 'optimistic-radio', value: StockMode.optimistic, groupValue: _stockMode, onChanged: _handleStockModeChange)
           ]),
         new MenuItem(
@@ -135,7 +135,7 @@ class StocksApp extends App {
           icon: 'action/thumb_down',
           onGestureTap: (event) => _handleStockModeChange(StockMode.pessimistic),
           children: [
-            new FlexExpandingChild(new Text('Pessimistic'), flex: 1),
+            new Flexible(child: new Text('Pessimistic')),
             new Radio(key: 'pessimistic-radio', value: StockMode.pessimistic, groupValue: _stockMode, onChanged: _handleStockModeChange)
           ]),
         new MenuDivider(key: 'div2'),