fix shrine

Samples/UIWidgetsSamples_2019_4/Assets/UIWidgetsGallery/demo/shrine/app.cs

         public override State createState() => new _ShrineAppState();
     }
 
-    public class _ShrineAppState : SingleTickerProviderStateMixin<ShrineApp> {//with SingleTickerProviderStateMixin {
+    public class _ShrineAppState : SingleTickerProviderStateMixin<ShrineApp> {
   
         AnimationController _controller;
       

Samples/UIWidgetsSamples_2019_4/Assets/UIWidgetsGallery/demo/shrine/backdrop.cs

         public override State createState() => new _BackdropState();
     }
 
-    public class _BackdropState : State<Backdrop> {//with SingleTickerProviderStateMixin { [!!!]
+    public class _BackdropState : SingleTickerProviderStateMixin<Backdrop> {
         public readonly GlobalKey _backdropKey =  GlobalKey.key(debugLabel: "Backdrop");
         AnimationController _controller;
         Animation<RelativeRect> _layerAnimation;

Samples/UIWidgetsSamples_2019_4/Assets/UIWidgetsGallery/demo/shrine/expanding_bottom_sheet.cs

 
 
 
-public class _ExpandingBottomSheetState : TickerProviderStateMixin<ExpandingBottomSheet> { //with TickerProviderStateMixin {
+public class _ExpandingBottomSheetState : TickerProviderStateMixin<ExpandingBottomSheet> { 
   public readonly GlobalKey _expandingBottomSheetKey = GlobalKey.key(debugLabel: "Expanding bottom sheet");
   
   float _width = expanding_buttom_sheetUtils._kWidthForCartIcon;

com.unity.uiwidgets/Runtime/material/button_theme.cs

                 hashCode = (hashCode * 397) ^ (_hoverColor != null ? _hoverColor.GetHashCode() : 0);
                 hashCode = (hashCode * 397) ^ (_highlightColor != null ? _highlightColor.GetHashCode() : 0);
                 hashCode = (hashCode * 397) ^ (_splashColor != null ? _splashColor.GetHashCode() : 0);
-                hashCode = (hashCode * 397) ^ colorScheme.GetHashCode();
+                hashCode = (hashCode * 397) ^ (colorScheme != null ? colorScheme.GetHashCode() : 0);
                 hashCode = (hashCode * 397) ^ _materialTapTargetSize.GetHashCode();
                 return hashCode;
             }