Imported Upstream version 3.6.0

Former-commit-id: da6be194a6b1221998fc28233f2503bd61dd9d14

external/aspnetwebstack/src/System.Web.Mvc/RequiredAttributeAdapter.cs

@@ -0,0 +1,20 @@
+// Copyright (c) Microsoft Corporation. All rights reserved. See License.txt in the project root for license information.
+
+using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations;
+
+namespace System.Web.Mvc
+{
+    public class RequiredAttributeAdapter : DataAnnotationsModelValidator<RequiredAttribute>
+    {
+        public RequiredAttributeAdapter(ModelMetadata metadata, ControllerContext context, RequiredAttribute attribute)
+            : base(metadata, context, attribute)
+        {
+        }
+
+        public override IEnumerable<ModelClientValidationRule> GetClientValidationRules()
+        {
+            return new[] { new ModelClientValidationRequiredRule(ErrorMessage) };
+        }
+    }
+}