[observe] use consistent comment style

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 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: $records');
- *       });
- *       // No changes are delivered until we check for them
- *       obj.damage(10);
- *       obj.damage(20);
- *       print('dirty checking!');
- *       Observable.dirtyCheck();
- *       print('done!');
- *     }
- *
- * A more sophisticated approach is to implement the change notification
- * manually. This avoids the potentially expensive [Observable.dirtyCheck]
- * operation, but requires more work in the object:
- *
- *     class Monster extends Unit with ChangeNotifier {
- *       int _health = 100;
- *       @reflectable get health => _health;
- *       @reflectable set health(val) {
- *         _health = notifyPropertyChange(#health, _health, val);
- *       }
- *
- *       void damage(int amount) {
- *         print('$this takes $amount damage!');
- *         health -= amount;
- *       }
- *
- *       toString() => 'Monster with $health hit points';
- *     }
- *
- *     main() {
- *       var obj = new Monster();
- *       obj.changes.listen((records) {
- *         print('Changes to $obj were: $records');
- *       });
- *       // Schedules asynchronous delivery of these changes
- *       obj.damage(10);
- *       obj.damage(20);
- *       print('done!');
- *     }
- *
- * *Note*: it is good practice to keep `@reflectable` annotation on
- * getters/setters so they are accessible via reflection. This will preserve
- * them from tree-shaking. You can also put this annotation on the class and it
- * preserve all of its members for reflection.
- *
- * [Tools](https://www.dartlang.org/polymer-dart/) exist to convert the first
- * form into the second form automatically, to get the best of both worlds.
- */
+/// Support for observing changes in model-view architectures.
+///
+/// **Warning:** This library is experimental, and APIs are subject to change.
+///
+/// This library is used to observe changes to [Observable] types. It also
+/// has helpers to make implementing and using [Observable] objects easy.
+///
+/// You can provide an observable object in two ways. The simplest way is to
+/// use dirty checking to discover changes automatically:
+///
+///     class Monster extends Unit with Observable {
+///       @observable int health = 100;
+///
+///       void damage(int amount) {
+///         print('$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: $records');
+///       });
+///       // No changes are delivered until we check for them
+///       obj.damage(10);
+///       obj.damage(20);
+///       print('dirty checking!');
+///       Observable.dirtyCheck();
+///       print('done!');
+///     }
+///
+/// A more sophisticated approach is to implement the change notification
+/// manually. This avoids the potentially expensive [Observable.dirtyCheck]
+/// operation, but requires more work in the object:
+///
+///     class Monster extends Unit with ChangeNotifier {
+///       int _health = 100;
+///       @reflectable get health => _health;
+///       @reflectable set health(val) {
+///         _health = notifyPropertyChange(#health, _health, val);
+///       }
+///
+///       void damage(int amount) {
+///         print('$this takes $amount damage!');
+///         health -= amount;
+///       }
+///
+///       toString() => 'Monster with $health hit points';
+///     }
+///
+///     main() {
+///       var obj = new Monster();
+///       obj.changes.listen((records) {
+///         print('Changes to $obj were: $records');
+///       });
+///       // Schedules asynchronous delivery of these changes
+///       obj.damage(10);
+///       obj.damage(20);
+///       print('done!');
+///     }
+///
+/// *Note*: it is good practice to keep `@reflectable` annotation on
+/// getters/setters so they are accessible via reflection. This will preserve
+/// them from tree-shaking. You can also put this annotation on the class and it
+/// preserve all of its members for reflection.
+///
+/// [Tools](https://www.dartlang.org/polymer-dart/) exist to convert the first
+/// form into the second form automatically, to get the best of both worlds.
 library observe;
 
 // This library contains code ported from observe-js:
 // https://github.com/Polymer/observe-js/blob/0152d542350239563d0f2cad39d22d3254bd6c2a/src/observe.js
 // We port what is needed for data bindings. Most of the functionality is
 // ported, except where differences are needed for Dart's Observable type.
 
 export 'src/bindable.dart';
 export 'src/bind_property.dart';
 export 'src/change_notifier.dart';
 export 'src/change_record.dart';
 export 'src/list_path_observer.dart';
 export 'src/list_diff.dart' show ListChangeRecord;
 export 'src/metadata.dart';
 export 'src/observable.dart' hide notifyPropertyChangeHelper, objectType;
 export 'src/observable_box.dart';
 export 'src/observable_list.dart';
 export 'src/observable_map.dart';
 export 'src/observer_transform.dart';
 export 'src/path_observer.dart';
 export 'src/to_observable.dart';