Rename UINode to Widget.

sky/sdk/lib/widgets/navigator.dart

Index: sky/sdk/lib/widgets/navigator.dart
diff --git a/sky/sdk/lib/widgets/navigator.dart b/sky/sdk/lib/widgets/navigator.dart
index dc4c0bc9ab28fd4d5007f81e7c3bae2cfeeafd76..4bbded3b71cc069c261c6a85a462d0ce1f4076c6 100644
--- a/sky/sdk/lib/widgets/navigator.dart
+++ b/sky/sdk/lib/widgets/navigator.dart
@@ -4,18 +4,18 @@
 
 import 'basic.dart';
 
-typedef UINode Builder(Navigator navigator);
+typedef Widget Builder(Navigator navigator);
 
 abstract class RouteBase {
   RouteBase({this.name});
   final String name;
-  UINode build(Navigator navigator);
+  Widget build(Navigator navigator);
 }
 
 class Route extends RouteBase {
   Route({String name, this.builder}) : super(name: name);
   final Builder builder;
-  UINode build(Navigator navigator) => builder(navigator);
+  Widget build(Navigator navigator) => builder(navigator);
 }
 
 class Navigator extends Component {
@@ -49,9 +49,9 @@ class Navigator extends Component {
     });
   }
 
-  UINode build() {
+  Widget build() {
     Route route = currentRoute == null ? routes[0] : currentRoute;
     assert(route != null);
     return route.build(this);
   }
-}
+}