update sliver_persistent_header mixin

com.unity.uiwidgets/Runtime/rendering/sliver_persistent_header.cs

         bool _lastOverlapsContent = false;
         public OverScrollHeaderStretchConfiguration stretchConfiguration;
 
-        protected void updateChild(float shrinkOffset, bool overlapsContent) {
+        protected virtual void updateChild(float shrinkOffset, bool overlapsContent) {
         }
 
         public override void markNeedsLayout() {

com.unity.uiwidgets/Runtime/widgets/sliver_persistent_header.cs

     public interface _RenderSliverPersistentHeaderForWidgetsMixin {
         _SliverPersistentHeaderElement _element { get; set; }
 
-        float? minExtent {
-            get;
-        }
-
-        float? maxExtent {
-            get;
-        }
-
-        void updateChild(float shrinkOffset, bool overlapsContent);
-    }
-    
-    public class _RenderSliverPersistentHeaderForWidgetsMixinOnRenderSliverPersistentHeader : RenderSliverPersistentHeader {
-        _SliverPersistentHeaderElement _element;
-
-        float? minExtent {
-            get {
-                return _element.widget.layoutDelegate.minExtent;
-            }
-        }
-
-        float? maxExtent {
-            get {
-                return _element.widget.layoutDelegate.minExtent;
-            }
-        }
-
-        void updateChild(float shrinkOffset, bool overlapsContent) {
-            D.assert(_element != null);
-            _element._build(shrinkOffset, overlapsContent);
-        }
-
-        void triggerRebuild() {
-            markNeedsLayout();
-        }
-        protected override void performLayout() {
-        }
     }
 
     class _SliverScrollingPersistentHeader : _SliverPersistentHeaderRenderObjectWidget {

com.unity.uiwidgets/Runtime/widgets/sliver_persistent_header.mixin.gen.cs

              }
          }
  
-         void updateChild(float shrinkOffset, bool overlapsContent) {
+         protected override void updateChild(float shrinkOffset, bool overlapsContent) {
              D.assert(_element != null);
              _element._build(shrinkOffset, overlapsContent);
          }
         }
-
-        void _RenderSliverPersistentHeaderForWidgetsMixin.updateChild(float shrinkOffset, bool overlapsContent) {
-            updateChild(shrinkOffset, overlapsContent);
-        }
         
         void triggerRebuild() {
             markNeedsLayout();
+            base.performLayout();
         }
     }
 
              }
          }
  
-         void updateChild(float shrinkOffset, bool overlapsContent) {
+         protected override void updateChild(float shrinkOffset, bool overlapsContent) {
              D.assert(_element != null);
              _element._build(shrinkOffset, overlapsContent);
          }
         }
-
-        void _RenderSliverPersistentHeaderForWidgetsMixin.updateChild(float shrinkOffset, bool overlapsContent) {
-            updateChild(shrinkOffset, overlapsContent);
-        }
         
         void triggerRebuild() {
             markNeedsLayout();
+            base.performLayout();
         }
     }
 
              }
          }
  
-         void updateChild(float shrinkOffset, bool overlapsContent) {
+         protected override void updateChild(float shrinkOffset, bool overlapsContent) {
              D.assert(_element != null);
              _element._build(shrinkOffset, overlapsContent);
          }
         }
-
-        void _RenderSliverPersistentHeaderForWidgetsMixin.updateChild(float shrinkOffset, bool overlapsContent) {
-            updateChild(shrinkOffset, overlapsContent);
-        }
         
         void triggerRebuild() {
             markNeedsLayout();
+            base.performLayout();
         }
     }
 
              }
          }
  
-         void updateChild(float shrinkOffset, bool overlapsContent) {
+         protected override void updateChild(float shrinkOffset, bool overlapsContent) {
              D.assert(_element != null);
              _element._build(shrinkOffset, overlapsContent);
          }
         }
-
-        void _RenderSliverPersistentHeaderForWidgetsMixin.updateChild(float shrinkOffset, bool overlapsContent) {
-            updateChild(shrinkOffset, overlapsContent);
-        }
         
         void triggerRebuild() {
             markNeedsLayout();
+            base.performLayout();
         }
     }
 

com.unity.uiwidgets/Runtime/widgets/sliver_persistent_header.mixin.njk

              }
          }
  
-         void updateChild(float shrinkOffset, bool overlapsContent) {
+         protected override void updateChild(float shrinkOffset, bool overlapsContent) {
              D.assert(_element != null);
              _element._build(shrinkOffset, overlapsContent);
          }
         }
-
-        void _RenderSliverPersistentHeaderForWidgetsMixin.updateChild(float shrinkOffset, bool overlapsContent) {
-            updateChild(shrinkOffset, overlapsContent);
-        }
         
         void triggerRebuild() {
             markNeedsLayout();
+            base.performLayout();
         }
     }
 {% endmacro %}
              }
          }
  
-         void updateChild(float shrinkOffset, bool overlapsContent) {
+         protected override void updateChild(float shrinkOffset, bool overlapsContent) {
              D.assert(_element != null);
              _element._build(shrinkOffset, overlapsContent);
          }
         }
-
-        void _RenderSliverPersistentHeaderForWidgetsMixin.updateChild(float shrinkOffset, bool overlapsContent) {
-            updateChild(shrinkOffset, overlapsContent);
-        }
         
         void triggerRebuild() {
             markNeedsLayout();
+            base.performLayout();
         }
     }
 {% endmacro %}
              }
          }
  
-         void updateChild(float shrinkOffset, bool overlapsContent) {
+         protected override void updateChild(float shrinkOffset, bool overlapsContent) {
              D.assert(_element != null);
              _element._build(shrinkOffset, overlapsContent);
          }
         }
-
-        void _RenderSliverPersistentHeaderForWidgetsMixin.updateChild(float shrinkOffset, bool overlapsContent) {
-            updateChild(shrinkOffset, overlapsContent);
-        }
         
         void triggerRebuild() {
             markNeedsLayout();
+            base.performLayout();
         }
     }
 {% endmacro %}
              }
          }
  
-         void updateChild(float shrinkOffset, bool overlapsContent) {
+         protected override void updateChild(float shrinkOffset, bool overlapsContent) {
              D.assert(_element != null);
              _element._build(shrinkOffset, overlapsContent);
          }
         }
-
-        void _RenderSliverPersistentHeaderForWidgetsMixin.updateChild(float shrinkOffset, bool overlapsContent) {
-            updateChild(shrinkOffset, overlapsContent);
-        }
         
         void triggerRebuild() {
             markNeedsLayout();
+            base.performLayout();
         }
     }
 {% endmacro %}