Upstream service worker "referer" tests to WPT

third_party/WebKit/LayoutTests/http/tests/serviceworker/resources/referrer-policy-iframe.html

-<script src="../../resources/get-host-info.js"></script>
-<script>
-function check_referer(url, expected_referer) {
-  return fetch(url)
-    .then(function(res) { return res.json(); })
-    .then(function(headers) {
-        if (headers['Referer'] === expected_referer) {
-          return Promise.resolve();
-        } else {
-          return Promise.reject('Referer for ' + url + ' must be ' +
-                                expected_referer + ' but got ' +
-                                headers['Referer']);
-        }
-      });
-}
-
-window.addEventListener('message', function(evt) {
-    var host_info = get_host_info();
-    var port = evt.ports[0];
-    check_referer('request-headers.php?ignore=true',
-                  host_info['HTTP_ORIGIN'] +
-                  '/serviceworker/resources/referrer-policy-iframe.html')
-      .then(function() {
-          return check_referer(
-              'request-headers.php?url=request-headers.php',
-              host_info['HTTP_ORIGIN'] + '/');
-        })
-      .then(function() { port.postMessage({results: 'finish'}); })
-      .catch(function(e) { port.postMessage({results: 'failure:' + e}); });
-  });
-</script>