demo updates

examples/material_gallery/lib/demo/tabs_demo.dart

@@ -22,21 +22,10 @@ class TabsDemo extends StatefulComponent {
 }
 
 class _TabsDemoState extends State<TabsDemo> {
-  double _viewWidth = 100.0;
-
-  void _handleSizeChanged(Size newSize) {
-    setState(() {
-      _viewWidth = newSize.width;
-    });
-  }
-
   Widget build(_) {
-    return new SizeObserver(
-      onSizeChanged: _handleSizeChanged,
-      child: new TabBarView<String>(
+    return new TabBarView<String>(
       selection: _selection,
       items: _iconNames,
-        itemExtent: _viewWidth,
       itemBuilder: (BuildContext context, String iconName, int index) {
         return new Container(
           key: new ValueKey<String>(iconName),
@@ -46,7 +35,6 @@ class _TabsDemoState extends State<TabsDemo> {
           )
         );
       }
-      )
     );
   }
 }

examples/stocks/lib/stock_home.dart

@@ -272,25 +272,15 @@ class StockHomeState extends State<StockHome> {
     );
   }
 
-  double _viewWidth = 100.0;
-  void _handleSizeChanged(Size newSize) {
-    setState(() {
-      _viewWidth = newSize.width;
-    });
-  }
-
   Widget build(BuildContext context) {
     return new Scaffold(
       key: _scaffoldKey,
       toolBar: _isSearching ? buildSearchBar() : buildToolBar(),
       floatingActionButton: buildFloatingActionButton(),
       drawer: _buildDrawer(context),
-      body: new SizeObserver(
-        onSizeChanged: _handleSizeChanged,
-        child: new TabBarView<StockHomeTab>(
+      body: new TabBarView<StockHomeTab>(
         selection: _tabBarSelection,
         items: <StockHomeTab>[StockHomeTab.market, StockHomeTab.portfolio],
-          itemExtent: _viewWidth,
         itemBuilder: (BuildContext context, StockHomeTab tab, _) {
           switch (tab) {
             case StockHomeTab.market:
@@ -302,7 +292,6 @@ class StockHomeState extends State<StockHome> {
           }
         }
       )
-      )
     );
   }
 }