anchor.diff:      var status = new BrowserTestingStatus(browser);
       browserStatus[new_id] = status;
       status.nextTestTimeout = createNextTestTimer(status);
  +    status.timeSinceRestart.start();
       browser.start(testingServer.getDriverUrl(new_id)).then((success) {
         // We may have started terminating in the mean time.
         if (underTermination) {
  
positive.code:   BrowserTest lastTest;
    bool timeout = false;
    Timer nextTestTimeout;
  
    BrowserTestingStatus(Browser this.browser);
  }
  
negative.code: class BrowserTestRunner {
    static const int MAX_NEXT_TEST_TIMEOUTS = 10;
    static const Duration NEXT_TEST_TIMEOUT = const Duration(seconds: 60);
    static const Duration RESTART_BROWSER_INTERVAL = const Duration(seconds: 60);
  
    final Map globalConfiguration;
    final bool checkedMode; // needed for dartium
  