Imported Upstream version 3.6.0

Former-commit-id: da6be194a6b1221998fc28233f2503bd61dd9d14

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

@@ -0,0 +1,41 @@
+namespace System.Web.Mvc {
+    using System;
+
+    [AttributeUsage(AttributeTargets.Class | AttributeTargets.Interface | AttributeTargets.Property, AllowMultiple = true)]
+    public sealed class AdditionalMetadataAttribute : Attribute, IMetadataAware {
+        private object _typeId = new object();
+
+        public AdditionalMetadataAttribute(string name, object value) {
+            if (name == null) {
+                throw new ArgumentNullException("name");
+            }
+
+            Name = name;
+            Value = value;
+        }
+
+        public override object TypeId {
+            get {
+                return _typeId;
+            }
+        }
+
+        public string Name {
+            get;
+            private set;
+        }
+
+        public object Value {
+            get;
+            private set;
+        }
+
+        public void OnMetadataCreated(ModelMetadata metadata) {
+            if (metadata == null) {
+                throw new ArgumentNullException("metadata");
+            }
+
+            metadata.AdditionalValues[Name] = Value;
+        }
+    }
+}