package:observe fix various api issues

pkg/polymer/test/build/all_phases_test.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.
 
 library polymer.test.build.all_phases_test;
 
 import 'package:polymer/transformer.dart';
 import 'package:polymer/src/build/script_compactor.dart' show MAIN_HEADER;
 import 'package:unittest/compact_vm_config.dart';
 
@@ skipping 163 matching lines @@
       'a|web/test2.html.0.dart': _sampleObservableOutput("A", "foo"),
       'a|web/b.dart': _sampleObservableOutput('B', 'bar'),
       'a|web/index.html.0.dart': _sampleObservableOutput("C", "car"),
     });
 }
 
 String _sampleObservable(String className, String fieldName) => '''
 library ${className}_$fieldName;
 import 'package:observe/observe.dart';
 
-class $className extends ObservableBase {
+class $className extends Observable {
   @observable int $fieldName;
   $className(this.$fieldName);
 }
 ''';
 
 String _sampleObservableOutput(String className, String field) =>
     "library ${className}_$field;\n"
     "import 'package:observe/observe.dart';\n\n"
-    "class $className extends ChangeNotifierBase {\n"
+    "class $className extends ChangeNotifier {\n"
     "  @reflectable @observable int get $field => __\$$field; "
       "int __\$$field; "
       "@reflectable set $field(int value) { "
       "__\$$field = notifyPropertyChange(#$field, __\$$field, value); "
       "}\n"
     "  $className($field) : __\$$field = $field;\n"
     "}\n";