Add |constraints| to Container for PopupMenuItem

sky/sdk/lib/framework/components2/popup_menu_item.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 'ink_well.dart';
 
 class PopupMenuItem extends Component {
-  static final Style _style = new Style('''
-    min-width: 112px;
-    padding: 16px;''');
-
   List<UINode> children;
   double opacity;
 
   PopupMenuItem({ Object key, this.children, this.opacity}) : super(key: key);
 
   UINode build() {
-    return new StyleNode(
-      new InkWell(
-        inlineStyle: opacity == null ? null : 'opacity: ${opacity}',
-        children: children
-      ),
-      _style);
+    return new Container(
+      constraints: const BoxConstraints(minWidth: 112.0),
+      padding: const EdgeDims.all(16.0),
+      // TODO(abarth): opacity: opacity,
+      child: new InkWell(children: children)
+    );
   }
 }