Imported Upstream version 3.6.0

Former-commit-id: da6be194a6b1221998fc28233f2503bd61dd9d14

external/aspnetwebstack/src/System.Web.Mvc/AjaxHelper`1.cs

@@ -0,0 +1,41 @@
+// Copyright (c) Microsoft Corporation. All rights reserved. See License.txt in the project root for license information.
+
+using System.Web.Routing;
+
+namespace System.Web.Mvc
+{
+    public class AjaxHelper<TModel> : AjaxHelper
+    {
+        private DynamicViewDataDictionary _dynamicViewDataDictionary;
+        private ViewDataDictionary<TModel> _viewData;
+
+        public AjaxHelper(ViewContext viewContext, IViewDataContainer viewDataContainer)
+            : this(viewContext, viewDataContainer, RouteTable.Routes)
+        {
+        }
+
+        public AjaxHelper(ViewContext viewContext, IViewDataContainer viewDataContainer, RouteCollection routeCollection)
+            : base(viewContext, viewDataContainer, routeCollection)
+        {
+            _viewData = new ViewDataDictionary<TModel>(viewDataContainer.ViewData);
+        }
+
+        public new dynamic ViewBag
+        {
+            get
+            {
+                if (_dynamicViewDataDictionary == null)
+                {
+                    _dynamicViewDataDictionary = new DynamicViewDataDictionary(() => ViewData);
+                }
+
+                return _dynamicViewDataDictionary;
+            }
+        }
+
+        public new ViewDataDictionary<TModel> ViewData
+        {
+            get { return _viewData; }
+        }
+    }
+}