Issue #3392125 by catch, Spokje: Random test failure in...

  protected function processChromeDriverPerformanceLogs(?string $service_name): PerformanceData {

    $attempts = 0;

    $lcp_count = 0;

    $request_count = 0;

    $response_count = 0;

    $messages = [];

    $session = $this->getSession();

    while ($attempts <= 30) {

        if ($message['method'] === 'Tracing.dataCollected' && $message['params']['name'] === 'largestContentfulPaint::Candidate') {

          $lcp_count++;

        }

        if ($message['method'] === 'Network.requestWillBeSent') {

          $request_count++;

        }

        if ($message['method'] === 'Network.responseReceived') {

          $response_count++;

        }

        $messages[] = $message;

      }

      // Only check once if $service_name is not set, since

      // largestContentfulPaint is not currently asserted on.

      if ($lcp_count === 2 || !isset($service_name)) {

      // Performance entries are logged indeterminately since page loading

      // varies by request. Chrome returns a response as soon as the HTML page

      // has returned to the browser, but CSS, JavaScript, image and AJAX

      // requests may all occur after this, and in turn trigger further requests

      // and page rendering events, and there is no performance log event for

      // the page loading 'finishing' since this is cannot be detected as such.

      // Therefore, continue collecting performance data until all of the

      // following are true, or until 30 seconds has passed:

      // - a largestContentfulPaint::candidate event has been fired

      // - all network requests have received a response

      // - no new performance log events have been recorded since the last

      //   iteration.

      if ($lcp_count && empty($performance_log) && ($request_count === $response_count)) {

        break;

      }

      sleep(1);