test

My project/Library/PackageCache/com.unity.ugui/Editor/UGUI/UI/PrefabLayoutRebuilder.cs

@@ -0,0 +1,24 @@
+using UnityEngine;
+using UnityEngine.UI;
+
+namespace UnityEditor.UI
+{
+    [InitializeOnLoad]
+    internal class PrefabLayoutRebuilder
+    {
+        static PrefabLayoutRebuilder()
+        {
+            PrefabUtility.prefabInstanceUpdated += OnPrefabInstanceUpdates;
+        }
+
+        static void OnPrefabInstanceUpdates(GameObject instance)
+        {
+            if (instance)
+            {
+                RectTransform rect = instance.transform as RectTransform;
+                if (rect)
+                    LayoutRebuilder.MarkLayoutForRebuild(rect);
+            }
+        }
+    }
+}