[mdv] implement Node.createBinding and Node.createBindings

pkg/observe/lib/src/change_record.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 observe;
 
 /** Records a change to an [Observable]. */
 abstract class ChangeRecord {
+  // TODO(jmesserly): rename this--it's confusing. Perhaps "matches"?
   /** True if the change affected the given item, otherwise false. */
-  bool change(key);
+  bool changes(key);
 }
 
 /** A change record to a field of an observable object. */
 class PropertyChangeRecord extends ChangeRecord {
   /** The field that was changed. */
   final Symbol field;
 
   PropertyChangeRecord(this.field);
 
   bool changes(key) => key is Symbol && field == key;
@@ skipping 27 matching lines @@
     // If this was a shift operation, anything after index is changed.
     if (addedCount != removedCount) return true;
 
     // Otherwise, anything in the update range was changed.
     return key < index + addedCount;
   }
 
   String toString() => '#<ListChangeRecord index: $index, '
       'removed: $removedCount, addedCount: $addedCount>';
 }