anchor.diff:  import 'path.dart';
   import 'utils.dart';
   
  -import 'reset_safari.dart' show
  -    killAndResetSafari;
  +import 'reset_safari.dart' show killAndResetSafari;
   
   class BrowserOutput {
     final StringBuffer stdout = new StringBuffer();
  
positive.code:         throw new AsyncError(error, stackTrace);
        }
      }
      Zone parent = Zone.current;
      ZoneSpecification specification = new ZoneSpecification(
          print: (Zone self, ZoneDelegate delegate, Zone zone, String line) {
            delegate.run(parent, () {
              _logEvent(line);
            });
          });
      Future zoneWrapper() {
        Uri safariUri = Uri.base.resolve(safariBundleLocation);
        return new Future(() => killAndResetSafari(bundle: safariUri))
  
negative.code: 
        return Directory.systemTemp.createTemp().then((userDir) {
          _cleanup = () {
            try {
              userDir.deleteSync(recursive: true);
            } catch (e) {
              _logEvent(
                  "Error: failed to delete Chrome user-data-dir ${userDir.path}"
                  ", will try again in 40 seconds: $e");
              new Timer(new Duration(seconds: 40), () {
                try {
                  userDir.deleteSync(recursive: true);
                } catch (e) {
                  _logEvent("Error: failed on second attempt to delete Chrome "
                      "user-data-dir ${userDir.path}: $e");
                }
              });
            }
          };
          var args = [
            "--user-data-dir=${userDir.path}",
  