Material and RaisedButton.

sky/sdk/lib/framework/widgets/wrappers.dart

Index: sky/sdk/lib/framework/widgets/wrappers.dart
diff --git a/sky/sdk/lib/framework/widgets/wrappers.dart b/sky/sdk/lib/framework/widgets/wrappers.dart
index 75eeb03fe06d4be7632f2292bc622bd718ea7c72..d1cdda925c495d5c297fd912646f10a974ae5486 100644
--- a/sky/sdk/lib/framework/widgets/wrappers.dart
+++ b/sky/sdk/lib/framework/widgets/wrappers.dart
@@ -127,6 +127,17 @@ class Padding extends OneChildRenderObjectWrapper {
 
 }
 
+class Center extends OneChildRenderObjectWrapper {
+
+  Center({ UINode child, Object key })
+    : super(child: child, key: key);
+
+  RenderPositionedBox get root { RenderPositionedBox result = super.root; return result; }
+
+  RenderPositionedBox createNode() => new RenderPositionedBox();
+
+}
+
 class SizedBox extends OneChildRenderObjectWrapper {
 
   SizedBox({