Make the popup menu work again.

This removes the requirement that things with the same type things have unique keys.
Now, anything without a key is assumed to be interchangeable.

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1178723010.

examples/stocks2/lib/stock_home.dart

@@ -114,38 +114,32 @@ class StockHome extends Component {
       children: [
         new DrawerHeader(children: [new Text('Stocks')]),
         new MenuItem(
-          key: 'Stock list',
           icon: 'action/assessment',
           children: [new Text('Stock List')]),
         new MenuItem(
-          key: 'Account Balance',
           icon: 'action/account_balance',
           children: [new Text('Account Balance')]),
-        new MenuDivider(key: 'div1'),
+        new MenuDivider(),
         new MenuItem(
-          key: 'Optimistic Menu Item',
           icon: 'action/thumb_up',
           onGestureTap: (event) => _handleStockModeChange(StockMode.optimistic),
           children: [
             new Flexible(child: new Text('Optimistic')),
-            new Radio(key: 'optimistic-radio', value: StockMode.optimistic, groupValue: _stockMode, onChanged: _handleStockModeChange)
+            new Radio(value: StockMode.optimistic, groupValue: _stockMode, onChanged: _handleStockModeChange)
           ]),
         new MenuItem(
-          key: 'Pessimistic Menu Item',
           icon: 'action/thumb_down',
           onGestureTap: (event) => _handleStockModeChange(StockMode.pessimistic),
           children: [
             new Flexible(child: new Text('Pessimistic')),
-            new Radio(key: 'pessimistic-radio', value: StockMode.pessimistic, groupValue: _stockMode, onChanged: _handleStockModeChange)
+            new Radio(value: StockMode.pessimistic, groupValue: _stockMode, onChanged: _handleStockModeChange)
           ]),
-        new MenuDivider(key: 'div2'),
+        new MenuDivider(),
         new MenuItem(
-          key: 'Settings',
           icon: 'action/settings',
           onGestureTap: (event) => _navigator.pushNamed('/settings'),
           children: [new Text('Settings')]),
         new MenuItem(
-          key: 'Help & Feedback',
           icon: 'action/help',
           children: [new Text('Help & Feedback')])
      ]

examples/stocks2/lib/stock_row.dart

@@ -27,16 +27,25 @@ class StockRow extends Component {
 
     List<Widget> children = [
       new Container(
-          child: new StockArrow(percentChange: stock.percentChange),
-          margin: const EdgeDims.only(right: 5.0)),
-      new Flexible(child: new Text(stock.symbol), flex: 2, key: "symbol"),
-      // TODO(hansmuller): text-align: right
-      new Flexible(child: new Text(lastSale,
-            style: const TextStyle(textAlign: TextAlign.right)),
-          key: "lastSale"),
-      new Flexible(child: new Text(changeInPrice,
-          style: typography.black.caption.copyWith(textAlign: TextAlign.right)),
-        key: "changeInPrice")
+        child: new StockArrow(percentChange: stock.percentChange),
+        margin: const EdgeDims.only(right: 5.0)
+      ),
+      new Flexible(
+        child: new Text(stock.symbol),
+        flex: 2
+      ),
+      new Flexible(
+        child: new Text(
+          lastSale,
+          style: const TextStyle(textAlign: TextAlign.right)
+        )
+      ),
+      new Flexible(
+        child: new Text(
+          changeInPrice,
+          style: typography.black.caption.copyWith(textAlign: TextAlign.right)
+        )
+      )
     ];
 
     // TODO(hansmuller): An explicit |height| shouldn't be needed

examples/stocks2/lib/stock_settings.dart

@@ -41,12 +41,11 @@ class StockSettings extends Component {
       decoration: new BoxDecoration(backgroundColor: colors.Grey[50]),
       child: new Block([
         new MenuItem(
-          key: 'Optimistic Setting',
           icon: 'action/thumb_up',
           onGestureTap: (event) => _handleAwesomeChanged(!_awesome),
           children: [
             new Flexible(child: new Text('Everything is awesome')),
-            new Checkbox(key: 'awesome', value: _awesome, onChanged: _handleAwesomeChanged)
+            new Checkbox(value: _awesome, onChanged: _handleAwesomeChanged)
           ]
         ),
       ])