Roll Observatory packages and add a roll script

packages/initialize/test/parts/bar.dart

 // Copyright (c) 2015, 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 web_components.init;
+part of initialize.initializer_parts_test;
 
-import 'dart:async';
-import 'src/init.dart';
+@initializeTracker
+class Bar2 {}
 
-Future main() => initWebComponents();
+@initializeTracker
+class Bar {}
+
+@initializeTracker
+bar2() {}
+
+@initializeTracker
+bar() {}