anchor.diff:        _logEvent("Got version: $version");
   
         return new Directory('').createTemp().then((userDir) {
  -        _cleanup = () { userDir.delete(recursive: true); };
  +        _cleanup = () { userDir.deleteSync(recursive: true); };
           var args = ["--user-data-dir=${userDir.path}", url,
                       "--disable-extensions", "--disable-popup-blocking",
                       "--bwsi", "--no-first-run"];
  
positive.code:   StringBuffer _stderr = new StringBuffer();
    StringBuffer _usageLog = new StringBuffer();
    // This function is called when the process is closed.
    // This is extracted to an external function so that we can do additional
    // functionality when the process closes (cleanup and call onExit)
    Function _processClosed;
    // This is called after the process is closed, after _processClosed has
    // been called, but before onExit. Subclasses can use this to cleanup
    // any browser specific resources (temp directories, profiles, etc)
    Function _cleanup;
  
    /** The version of the browser - normally set when starting a browser */
  
negative.code:       browserTerminationFuture = completer.future;
  
        if (process != null) {
          _processClosedCompleter.future.then((_) {
            process = null;
            completer.complete(true);
            if (_cleanup != null) {
              _cleanup();
            }
          });
  
          if (process.kill(ProcessSignal.SIGKILL)) {
            _logEvent("Successfully sent kill signal to process.");
  