Roll Observatory packages and add a roll script

packages/barback/test/transformer/lazy_check_content_and_rename.dart

+// Copyright (c) 2014, 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 barback.test.transformer.lazy_check_content_and_rename;
+
+import 'dart:async';
+
+import 'package:barback/barback.dart';
+
+import 'declaring_check_content_and_rename.dart';
+
+class LazyCheckContentAndRenameTransformer
+    extends DeclaringCheckContentAndRenameTransformer
+    implements LazyTransformer {
+  LazyCheckContentAndRenameTransformer({String oldExtension,
+        String oldContent, String newExtension, String newContent})
+      : super(oldExtension: oldExtension, oldContent: oldContent,
+              newExtension: newExtension, newContent: newContent);
+}