webpage.html | Explore in Territory

<!doctype html>
<script type="text/javascript">
  window.testIframe = function(extensionId, iframeSrc) {
    var iframe = document.createElement('iframe');
    var responseSent = false;

    return new Promise(resolve => {
      window.onmessage = function(e) {
        if (!responseSent) {
          responseSent = true;
          resolve(e.data);
          document.body.removeChild(iframe);
        }
      };

      iframe.onload = function() {
        iframe.contentWindow.postMessage('ping', '*');
      };

      iframe.src = 'chrome-extension://' + extensionId + '/' + iframeSrc;
      document.body.appendChild(iframe);
    });
  };
</script>

chromium/chrome/test/data/extensions/api_test/service_worker/web_accessible_resources/webpage.html