Rename UINode to Widget.

sky/sdk/lib/widgets/tool_bar.dart

Index: sky/sdk/lib/widgets/tool_bar.dart
diff --git a/sky/sdk/lib/widgets/tool_bar.dart b/sky/sdk/lib/widgets/tool_bar.dart
index 36557b373913dbd275ed4cd7d6466f11b8582c0f..462d42bbbc9b4c0f152cfb0133ef249b505ae233 100644
--- a/sky/sdk/lib/widgets/tool_bar.dart
+++ b/sky/sdk/lib/widgets/tool_bar.dart
@@ -17,13 +17,13 @@ class ToolBar extends Component {
     this.backgroundColor
   }) : super(key: key);
 
-  final UINode left;
-  final UINode center;
-  final List<UINode> right;
+  final Widget left;
+  final Widget center;
+  final List<Widget> right;
   final Color backgroundColor;
 
-  UINode build() {
-    List<UINode> children = new List<UINode>();
+  Widget build() {
+    List<Widget> children = new List<Widget>();
     if (left != null)
       children.add(left);