change to source-order crawling of directives instead of alphabetical

test/parts/foo.dart

Index: test/parts/foo.dart
diff --git a/test_package/lib/bar.dart b/test/parts/foo.dart
similarity index 73%
copy from test_package/lib/bar.dart
copy to test/parts/foo.dart
index 8cc6129cdc024e3511a7622f98d90270f34ec05e..2c0528f545820e5165bf7859230c36b048be1da1 100644
--- a/test_package/lib/bar.dart
+++ b/test/parts/foo.dart
@@ -1,7 +1,10 @@
 // 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.
+part of initialize.initializer_parts_test;
+
 @initializeTracker
-library test_package.bar;
+class Foo {}
 
-import 'package:initialize/src/initialize_tracker.dart';
+@initializeTracker
+foo() {}