Also share (almost identicial) code between
error_at_exit_spawn_test.dart
error_at_exit_spawnuri_test.dart
in
error_at_exit_spawning_shared.dart
Converted 3 tests away from package:unittest to use package:async_helper/package:expect.
Change-Id: I1b9bf7c895eb21f3c5be9246e69b784296610ce3
Reviewed-on: https://dart-review.googlesource.com/5261
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Lasse R.H. Nielsen <lrn@google.com>
Martin Kustermann