Fix broken test: closed_world2 test still uses rasta
Fix broken test: closed_world2 test still uses rasta

R=sra@google.com

Review-Url: https://codereview.chromium.org/2994813002 .

dartino/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dartino/dart-sdk,dartino/dart-sdk,dartino/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dart-lang/sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dart-lang/sdk,dart-archive/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dart-lang/sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk