Make the StockList actually work in stocks2

sky/sdk/lib/framework/components2/scaffold.dart

Index: sky/sdk/lib/framework/components2/scaffold.dart
diff --git a/sky/sdk/lib/framework/components2/scaffold.dart b/sky/sdk/lib/framework/components2/scaffold.dart
index ea6c3797b35b4da035ff55c93605c46292125f6b..1bcf867953489aa98bf83d8442fa87b4d29df06c 100644
--- a/sky/sdk/lib/framework/components2/scaffold.dart
+++ b/sky/sdk/lib/framework/components2/scaffold.dart
@@ -46,6 +46,22 @@ class RenderScaffold extends RenderBox {
     markNeedsLayout();
   }
 
+  void attachChildren() {
+    for (ScaffoldSlots slot in [ScaffoldSlots.body, ScaffoldSlots.statusBar, ScaffoldSlots.toolbar, ScaffoldSlots.floatingActionButton, ScaffoldSlots.drawer]) {
+      RenderBox box = _slots[slot];
+      if (box != null)
+        box.attach();
+    }
+  }
+
+  void detachChildren() {
+    for (ScaffoldSlots slot in [ScaffoldSlots.body, ScaffoldSlots.statusBar, ScaffoldSlots.toolbar, ScaffoldSlots.floatingActionButton, ScaffoldSlots.drawer]) {
+      RenderBox box = _slots[slot];
+      if (box != null)
+        box.detach();
+    }
+  }
+
   ScaffoldSlots remove(RenderBox child) {
     assert(child != null);
     for (ScaffoldSlots slot in ScaffoldSlots.values) {