Roll Observatory packages and add a roll script

packages/initialize/lib/src/static_loader.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 initialize.static_loader;
 
 import 'dart:collection' show Queue;
 import 'package:initialize/initialize.dart';
 
 /// This represents an annotation/declaration pair.
 class InitEntry<T> {
@@ skipping 31 matching lines @@
   };
 
   result.addAll(initializers
       .where(matchesFilters)
       .map((i) => () => i.meta.initialize(i.target)));
 
   initializers.removeWhere(matchesFilters);
 
   return result;
 }