Revert "Converting Polymer and TemplateElement to use deprecated Node.document"

pkg/mdv/lib/src/input_bindings.dart

Index: pkg/mdv/lib/src/input_bindings.dart
diff --git a/pkg/mdv/lib/src/input_bindings.dart b/pkg/mdv/lib/src/input_bindings.dart
index fa158410d1f39d402d5e11d6464cfaa268e49868..b5467aa55e5342646ab64f71f19b408da192efc7 100644
--- a/pkg/mdv/lib/src/input_bindings.dart
+++ b/pkg/mdv/lib/src/input_bindings.dart
@@ -114,7 +114,7 @@ class _CheckedBinding extends _InputBinding {
             el.name == element.name;
       });
     } else {
-      var radios = element.document.queryAll(
+      var radios = element.ownerDocument.queryAll(
           'input[type="radio"][name="${element.name}"]');
       return radios.where((el) => el != element && el.form == null);
     }