chromium/chrome/test/data/notifications/android_test.html

<!doctype html>
<html lang="en">
  <head>
    <meta charset="utf-8">
    <title>Android Web Notifications Instrumentation test-page</title>
  </head>
  <body>
    <!-- This page is used by the NotificationPlatformBridgeTest instrumentation
         test suite on Android. -->
    <script src="notification_test_utils.js"></script>
    <script>
      function GetActivatedServiceWorkerForTest() {
        return GetActivatedServiceWorker(
            'android_test_worker.js', location.pathname);
      }

      function SetupReplyForwardingForTests() {
        GetActivatedServiceWorkerForTest()
            .then(registration => {
              messagePort.addEventListener('message', function replyListener(event) {
                if (event.data.startsWith('reply: ')) {
                  messagePort.removeEventListener('message', replyListener);
                  sendToTest(event.data);
                }});
            })
            .catch(sendToTest);
      }

      // NotificationPlatformBridgeTest observes changes to the tab title as an
      // asynchronous response mechanism from JavaScript to Java.
      var errorCounter = 0;
      function sendToTest(message) {
        // Duplicate messages cannot be detected by the test, don't send them.
        if (message == document.title) {
          console.log('Duplicate message: ' + message);
          message =
              'Error ' + errorCounter + ' - duplicate message: ' + message;
          errorCounter++;
        }
        document.title = message;
      }

      // Some tests require a count of how frequently they were invoked.
      var message_counts = {}
      function addCountAndSendToTest(message) {
        if (message in message_counts) {
          message_counts[message]++;
        } else {
          message_counts[message] = 1;
        }
        document.title = message + ': ' + message_counts[message];
      }
    </script>
  </body>
</html>