update sample

Samples/UIWidgetsSamples_2019_4/Assets/Editor/Widgets.cs

             var mediaQueryData = MediaQuery.of(context);
             var px = mediaQueryData.size.width / 2;
             var py = mediaQueryData.size.width / 2;
-
+            var transform = new Matrix4().translationValues(px, py, 0);
+            transform.rotateZ(Mathf.PI / 180 * 5);
-                        transform: Matrix3.makeRotate(Mathf.PI / 180 * 5, px, py),
+                        transform: transform,
                         child:
                         new Column(
                             children: new List<Widget> {

Samples/UIWidgetsSamples_2019_4/Assets/UIWidgetsGallery/demo/animation/widgets.cs

         );
 
         public override Widget build(BuildContext context) {
+            var scale = this.scale ?? 1.0f;
-                        transform: Matrix3.makeScale(this.scale ?? 1.0f),
+                        transform: new Matrix4().diagonal3Values(scale, scale, scale),
                         alignment: Alignment.center,
                         child: new Stack(
                             children: new List<Widget> {