Imported Upstream version 3.6.0

Former-commit-id: da6be194a6b1221998fc28233f2503bd61dd9d14

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

@@ -0,0 +1,21 @@
+// Copyright (c) Microsoft Corporation. All rights reserved. See License.txt in the project root for license information.
+
+namespace System.Web.Mvc
+{
+    [AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, AllowMultiple = false, Inherited = true)]
+    public sealed class ChildActionOnlyAttribute : FilterAttribute, IAuthorizationFilter
+    {
+        public void OnAuthorization(AuthorizationContext filterContext)
+        {
+            if (filterContext == null)
+            {
+                throw new ArgumentNullException("filterContext");
+            }
+
+            if (!filterContext.IsChildAction)
+            {
+                throw Error.ChildActionOnlyAttribute_MustBeInChildRequest(filterContext.ActionDescriptor);
+            }
+        }
+    }
+}