Imported Upstream version 3.6.0

Former-commit-id: da6be194a6b1221998fc28233f2503bd61dd9d14

mcs/class/System.Web.Mvc3/Mvc/AllowHtmlAttribute.cs

@@ -0,0 +1,19 @@
+namespace System.Web.Mvc {
+    using System;
+
+    // This attribute can be applied to a model property to specify that the particular property to
+    // which it is applied should not go through request validation.
+
+    [AttributeUsage(AttributeTargets.Property, AllowMultiple = false, Inherited = true)]
+    public sealed class AllowHtmlAttribute : Attribute, IMetadataAware {
+
+        public void OnMetadataCreated(ModelMetadata metadata) {
+            if (metadata == null) {
+                throw new ArgumentNullException("metadata");
+            }
+
+            metadata.RequestValidationEnabled = false;
+        }
+
+    }
+}