Implement radio button for Sky’s fn2

sky/engine/core/painting/Paint.idl

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 [
   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;
 
   // TODO(mpcomplete): remove this in favor of assigning to |color|.
   void setARGB(unsigned long a, unsigned long r, unsigned long g, unsigned long b);
   void setDrawLooper(DrawLooper looper);
   void setColorFilter(ColorFilter filter);
   void setMaskFilter(MaskFilter filter);
   void setTransferMode(TransferMode transferMode);
 };