Remove redundant Paint.setARGB in favor of assigning to Paint.color.

sky/examples/raw/custom_paint_without_element.sky

Index: sky/examples/raw/custom_paint_without_element.sky
diff --git a/sky/examples/raw/custom_paint_without_element.sky b/sky/examples/raw/custom_paint_without_element.sky
index d18611070edd8ae6786ce8919c4b65ef14ef5627..72a6c2f41dba5a16de623d47ef8bac3d043e72da 100644
--- a/sky/examples/raw/custom_paint_without_element.sky
+++ b/sky/examples/raw/custom_paint_without_element.sky
@@ -9,7 +9,7 @@ void main() {
   PictureRecorder recorder = new PictureRecorder(width, height);
   double radius = min(width, height) * 0.45;
 
-  Paint paint = new Paint()..setARGB(255, 0, 255, 0);
+  Paint paint = new Paint()..color = Color.fromARGB(255, 0, 255, 0);
 
   recorder.drawCircle(width / 2, height / 2, radius, paint);