Upstream service worker "referer" tests to WPT

third_party/WebKit/LayoutTests/external/wpt/service-workers/service-worker/resources/referrer-policy-iframe.html

-<script src="../../resources/get-host-info.js"></script>
+<script src="/common/get-host-info.sub.js"></script>
+<script src="test-helpers.sub.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) {
+        if (headers['referer'] === expected_referer) {
           return Promise.resolve();
         } else {
           return Promise.reject('Referer for ' + url + ' must be ' +
                                 expected_referer + ' but got ' +
-                                headers['Referer']);
+                                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')
+    check_referer('request-headers.py?ignore=true',
+                  host_info['HTTPS_ORIGIN'] +
+                  base_path() + 'referrer-policy-iframe.html')
       .then(function() {
           return check_referer(
-              'request-headers.php?url=request-headers.php',
-              host_info['HTTP_ORIGIN'] + '/');
+              'request-headers.py?url=request-headers.py',
+              host_info['HTTPS_ORIGIN'] + '/');
         })
       .then(function() { port.postMessage({results: 'finish'}); })
       .catch(function(e) { port.postMessage({results: 'failure:' + e}); });
   });
 </script>