chromium/third_party/blink/web_tests/external/wpt/navigation-timing/prefetch-transfer-size-iframe.html

<!DOCTYPE html>
<html>

<head>
  <title>Navigation Timing Transfert Size of Prefetched Page</title>
  <script src="/resources/testharness.js"></script>
  <script src="/resources/testharnessreport.js"></script>
  <script src="/common/utils.js"></script>
  <script src="/common/dispatcher/dispatcher.js"></script>
</head>

<body>
  <script>
    function add_iframe(url) {
      return new Promise(resolve => {
        const frame = document.createElement('iframe');
        frame.src = url;
        frame.addEventListener('load', () => {
          resolve(frame);
        }, { once: true });
        document.body.appendChild(frame);
      });
    };

    promise_test(async t => {
      // Add an iframe
      let iframe_url = 'resources/iframe-prefetch-transfer-size.html';
      frame = await add_iframe(iframe_url)

      // Prefetch a url as link element.
      await frame.contentWindow.addLink();

      // navigate to the prefetched url.
      await new Promise(resolve => {
        frame.addEventListener('load', () => {
          resolve();
        }, { once: true });
        frame.contentWindow.navigateToPrefetchedUrl();
      });

      // Verify navigation timing transfer size is 0.;
      let transferSize =
        frame.contentWindow.performance.getEntriesByType('navigation')[0].transferSize;

      assert_equals(transferSize, 0);

    }, "Navigation timing transfer size for a prefetched navigation should be 0.");
  </script>
</body>

</html>