Fix bustage from my previous CL: "Color.fromARGB" becomes "new Color.fromARGB".

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 72a6c2f41dba5a16de623d47ef8bac3d043e72da..cf36a2b4ed6086c86e4acbcbfef1472fc13c7843 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()..color = Color.fromARGB(255, 0, 255, 0);
+  Paint paint = new Paint()..color = const Color.fromARGB(255, 0, 255, 0);
 
   recorder.drawCircle(width / 2, height / 2, radius, paint);