Use "package:" imports for pub.

test/global/deactivate/missing_package_arg_test.dart

Index: test/global/deactivate/missing_package_arg_test.dart
diff --git a/test/global/deactivate/missing_package_arg_test.dart b/test/global/deactivate/missing_package_arg_test.dart
index 482947da1845d781844787bdcfa79bc5620370bf..f095856e666b152d3fa433293b0e9552f11b9bb1 100644
--- a/test/global/deactivate/missing_package_arg_test.dart
+++ b/test/global/deactivate/missing_package_arg_test.dart
@@ -2,7 +2,8 @@
 // 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.
 
-import '../../../lib/src/exit_codes.dart' as exit_codes;
+import 'package:pub/src/exit_codes.dart' as exit_codes;
+
 import '../../test_pub.dart';
 
 main() {