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

sky/examples/raw/draw_picture_into_canvas.sky

Index: sky/examples/raw/draw_picture_into_canvas.sky
diff --git a/sky/examples/raw/draw_picture_into_canvas.sky b/sky/examples/raw/draw_picture_into_canvas.sky
index 6b8024d9ba13b9ca7f471a6a99618dd8aff30c37..baf041d1d2b6ab1f1cfaf69cf6a5b3df8344d9fc 100644
--- a/sky/examples/raw/draw_picture_into_canvas.sky
+++ b/sky/examples/raw/draw_picture_into_canvas.sky
@@ -15,7 +15,7 @@ void main() {
   Picture stamp = stampRecorder.endRecording();
 
   PictureRecorder recorder = new PictureRecorder(width, height);
-  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(50.0, 50.0, 50.0, paint);
   recorder.translate(10.0, 10.0);
   recorder.drawPicture(stamp);