Make the StockList actually work in stocks2

sky/sdk/lib/framework/components2/scaffold.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 '../fn2.dart';
 import 'dart:sky' as sky;
 import '../rendering/box.dart';
 import '../rendering/object.dart';
 
 
@@ skipping 28 matching lines @@
     if (old == value)
       return;
     if (old != null)
       dropChild(old);
     _slots[slot] = value;
     if (value != null)
       adoptChild(value);
     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) {
       if (_slots[slot] == child) {
         this[slot] = null;
         return slot;
       }
     }
     return null;
   }
@@ skipping 115 matching lines @@
   void syncRenderObject(UINode old) {
     super.syncRenderObject(old);
     syncChild(toolbar, old is Scaffold ? old.toolbar : null, ScaffoldSlots.toolbar);
     syncChild(body, old is Scaffold ? old.body : null, ScaffoldSlots.body);
     syncChild(statusbar, old is Scaffold ? old.statusbar : null, ScaffoldSlots.statusBar);
     syncChild(drawer, old is Scaffold ? old.drawer : null, ScaffoldSlots.drawer);
     syncChild(floatingActionButton, old is Scaffold ? old.floatingActionButton : null, ScaffoldSlots.floatingActionButton);
   }
 
 }