Implement radio button for Sky’s fn2

sky/engine/core/painting/Paint.idl

Index: sky/engine/core/painting/Paint.idl
diff --git a/sky/engine/core/painting/Paint.idl b/sky/engine/core/painting/Paint.idl
index 27f4b20b3532b890b073768aa1e7076d27e0559e..f86cc75451581f64776efdb4042583f2864b2f7b 100644
--- a/sky/engine/core/painting/Paint.idl
+++ b/sky/engine/core/painting/Paint.idl
@@ -5,6 +5,14 @@
 [
   Constructor(),
 ] interface Paint {
+  // Style
+  const unsigned short FILL_STYLE            = 0;
+  const unsigned short STROKE_STYLE          = 1;
+  const unsigned short STROKE_AND_FILL_STYLE = 2;
+
+  // TODO(jackson): we could wrap this enum like we did for |color|
+  attribute unsigned short style;
+  attribute float strokeWidth;
   attribute boolean isAntiAlias;
   attribute Color color;