package:observe fix various api issues

pkg/observe/lib/observe.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.
 
 /**
  * Support for observing changes in model-view architectures.
  *
  * **Warning:** This library is experimental, and APIs are subject to change.
  *
  * This library is used to observe changes to [Observable] types. It also
  * has helpers to make implementing and using [Observable] objects easy.
  *
  * You can provide an observable object in two ways. The simplest way is to
  * use dirty checking to discover changes automatically:
  *
- *     class Monster extends Unit with ObservableMixin {
+ *     class Monster extends Unit with Observable {
  *       @observable int health = 100;
  *
  *       void damage(int amount) {
  *         print('$this takes $amount damage!');
  *         health -= amount;
  *       }
  *
  *       toString() => 'Monster with $health hit points';
  *     }
  *
  *     main() {
  *       var obj = new Monster();
  *       obj.changes.listen((records) {
  *         print('Changes to $obj were: $records');
  *       });
  *       // No changes are delivered until we check for them
  *       obj.damage(10);
  *       obj.damage(20);
  *       print('dirty checking!');
  *       Observable.dirtyCheck();
  *       print('done!');
  *     }
  *
  * A more sophisticated approach is to implement the change notification
  * manually. This avoids the potentially expensive [Observable.dirtyCheck]
  * operation, but requires more work in the object:
  *
- *     class Monster extends Unit with ChangeNotifierMixin {
+ *     class Monster extends Unit with ChangeNotifier {
  *       int _health = 100;
  *       @reflectable get health => _health;
  *       @reflectable set health(val) {
  *         _health = notifyPropertyChange(#health, _health, val);
  *       }
  *
  *       void damage(int amount) {
  *         print('$this takes $amount damage!');
  *         health -= amount;
  *       }
@@ skipping 26 matching lines @@
 import 'dart:collection';
 
 // Note: ObservableProperty is in this list only for the unusual use case of
 // dart2js without deploy tool. The deploy tool (see "transformer.dart") will
 // add the @reflectable annotation, which makes it work with Polymer's
 // @published.
 @MirrorsUsed(metaTargets: const [Reflectable, ObservableProperty],
     override: 'observe')
 import 'dart:mirrors';
 
+import 'package:meta/meta.dart';
+
 // Note: this is an internal library so we can import it from tests.
 // TODO(jmesserly): ideally we could import this with a prefix, but it caused
 // strange problems on the VM when I tested out the dirty-checking example
 // above.
 import 'src/dirty_check.dart';
 
 part 'src/bind_property.dart';
 part 'src/change_notifier.dart';
 part 'src/change_record.dart';
 part 'src/compound_binding.dart';
 part 'src/list_path_observer.dart';
 part 'src/metadata.dart';
 part 'src/observable.dart';
 part 'src/observable_box.dart';
 part 'src/observable_list.dart';
 part 'src/observable_map.dart';
 part 'src/path_observer.dart';
 part 'src/to_observable.dart';