Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Web/ModelBinding/DictionaryModelBinder`2.cs

@@ -0,0 +1,12 @@
+namespace System.Web.ModelBinding {
+    using System.Collections.Generic;
+
+    public class DictionaryModelBinder<TKey, TValue> : CollectionModelBinder<KeyValuePair<TKey, TValue>> {
+
+        protected override bool CreateOrReplaceCollection(ModelBindingExecutionContext modelBindingExecutionContext, ModelBindingContext bindingContext, IList<KeyValuePair<TKey, TValue>> newCollection) {
+            CollectionModelBinderUtil.CreateOrReplaceDictionary(bindingContext, newCollection, () => new Dictionary<TKey, TValue>());
+            return true;
+        }
+
+    }
+}