update polymer, nodebind, and templatebinding

pkg/template_binding/lib/src/text_area_element.dart

Index: pkg/template_binding/lib/src/text_area_element.dart
diff --git a/pkg/template_binding/lib/src/text_area_element.dart b/pkg/template_binding/lib/src/text_area_element.dart
index 361f7c1a138a7413701fbee39d29704390609aa4..89fdf0c0ad306236d39ff6c253a483d2814366e0 100644
--- a/pkg/template_binding/lib/src/text_area_element.dart
+++ b/pkg/template_binding/lib/src/text_area_element.dart
@@ -13,13 +13,12 @@ class _TextAreaElementExtension extends _ElementExtension {
   Bindable bind(String name, value, {bool oneTime: false}) {
     if (name != 'value') return super.bind(name, value, oneTime: oneTime);
 
+    _node.attributes.remove(name);
     if (oneTime) {
       _InputBinding._updateProperty(_node, value, name);
       return null;
     }
 
-    _self.unbind(name);
-    _node.attributes.remove(name);
-    return bindings[name] = new _InputBinding(_node, value, name);
+    return _maybeUpdateBindings(name, new _InputBinding(_node, value, name));
   }
 }