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

sky/examples/raw/spinning_square.dart

Index: sky/examples/raw/spinning_square.dart
diff --git a/sky/examples/raw/spinning_square.dart b/sky/examples/raw/spinning_square.dart
index 97c3c7ab413ace874edd4986b93b1c595672f71d..5613248e4bdc26a5bfe7c90abe8313801e3760cd 100644
--- a/sky/examples/raw/spinning_square.dart
+++ b/sky/examples/raw/spinning_square.dart
@@ -16,7 +16,7 @@ void beginFrame(double timeStamp) {
   canvas.translate(view.width / 2.0, view.height / 2.0);
   canvas.rotate(math.PI * delta / 1800);
   canvas.drawRect(new Rect.fromLTRB(-100.0, -100.0, 100.0, 100.0),
-                  new Paint()..setARGB(255, 0, 255, 0));
+                  new Paint()..color = Color.fromARGB(255, 0, 255, 0));
   view.picture = canvas.endRecording();
   view.scheduleFrame();
   tracing.end('beginFrame');