Give the popup menu a 2px border radius

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

Index: sky/sdk/lib/framework/components2/popup_menu.dart
diff --git a/sky/sdk/lib/framework/components2/popup_menu.dart b/sky/sdk/lib/framework/components2/popup_menu.dart
index 184a627891abc551038ce83ab77216dc63d56660..2f9058f7ed5c2b669da51031bfd31be4f5079bd8 100644
--- a/sky/sdk/lib/framework/components2/popup_menu.dart
+++ b/sky/sdk/lib/framework/components2/popup_menu.dart
@@ -99,13 +99,13 @@ class PopupMenu extends AnimatedComponent {
       return new PopupMenuItem(key: i++, children: item, opacity: opacity);
     }));
 
-    // border-radius: 2px
     // inlineStyle: _inlineStyle(),
     return new ShrinkWrapWidth(
       child: new Container(
         padding: const EdgeDims.all(8.0),
         decoration: new BoxDecoration(
           backgroundColor: Grey[50],
+          borderRadius: 2.0,
           boxShadow: Shadow[level]),
         child: new BlockContainer(children: children)
       )