merge to trunk all changes from 36817 until 37378 under the packages: polymer,

pkg/template_binding/lib/src/text_area_element.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of template_binding;
 
 /** Extensions to the [TextAreaElement] API. */
 class _TextAreaElementExtension extends _ElementExtension {
   _TextAreaElementExtension(TextAreaElement node) : super(node);
 
   TextAreaElement get _node => super._node;
 
   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));
   }
 }