--- a/testing/web-platform/tests/referrer-policy/generic/common.js
+++ b/testing/web-platform/tests/referrer-policy/generic/common.js
@@ -106,17 +106,17 @@ function queryIframe(url, callback, refe
       return;
 
     callback(event.data, url);
     window.removeEventListener("message", listener);
   }
   window.addEventListener("message", listener);
 }
 
-function queryImage(url, callback, attributes, referrerPolicy) {
+function queryImage(url, callback, attributes, referrerPolicy, test) {
   // For images, we'll test:
   // - images in a `srcdoc` frame to ensure that it uses the referrer
   //   policy of its parent,
   // - images in a top-level document,
   // - and images in a `srcdoc` frame with its own referrer policy to
   //   override its parent.
 
   var noSrcDocPolicy = new Promise((resolve, reject) => {
@@ -147,21 +147,21 @@ function queryImage(url, callback, attri
   });
 
   var pagePolicy = new Promise((resolve, reject) => {
     loadImageInWindow(url, function (img) {
       resolve(decodeImageData(extractImageData(img)));
     }, attributes, window);
   });
 
-  Promise.all([noSrcDocPolicy, srcDocPolicy, pagePolicy]).then(values => {
+  Promise.all([noSrcDocPolicy, srcDocPolicy, pagePolicy]).then(test.step_func(values => {
     assert_equals(values[0].headers.referer, values[2].headers.referer, "Referrer inside 'srcdoc' without its own policy should be the same as embedder's referrer.");
     assert_equals((iframePolicy === "no-referrer" ? undefined : document.location.href), values[1].headers.referer, "Referrer inside 'srcdoc' should use the iframe's policy if it has one");
     callback(wrapResult(url, values[2]), url);
-  });
+  }));
 }
 
 function queryXhr(url, callback) {
   var xhr = new XMLHttpRequest();
   xhr.open('GET', url, true);
   xhr.onreadystatechange = function(e) {
     if (this.readyState == 4 && this.status == 200) {
       var server_data = JSON.parse(this.responseText);

--- a/testing/web-platform/tests/referrer-policy/generic/referrer-policy-test-case.js
+++ b/testing/web-platform/tests/referrer-policy/generic/referrer-policy-test-case.js
@@ -65,34 +65,36 @@ function ReferrerPolicyTestCase(scenario
                           "?redirection=" + t._scenario["redirection"] +
                           "&cache_destroyer=" + (new Date()).getTime();
     },
 
     _constructExpectedReferrerUrl: function() {
       t._expectedReferrerUrl = referrerUrlResolver[t._scenario.referrer_url]();
     },
 
-    _invokeSubresource: function(callback) {
+    _invokeSubresource: function(callback, test) {
       var invoker = subresourceInvoker[t._scenario.subresource];
 
       // Depending on the delivery method, extend the subresource element with
       // these attributes.
       var elementAttributesForDeliveryMethod = {
         "attr-referrer":  {referrerPolicy: t._scenario.referrer_policy},
         "rel-noreferrer": {rel: "noreferrer"}
       };
 
       var delivery_method = t._scenario.delivery_method;
 
       if (delivery_method in elementAttributesForDeliveryMethod) {
         invoker(t._subresourceUrl,
                 callback,
-                elementAttributesForDeliveryMethod[delivery_method], t._scenario.referrer_policy);
+                elementAttributesForDeliveryMethod[delivery_method],
+                t._scenario.referrer_policy,
+                test);
       } else {
-        invoker(t._subresourceUrl, callback, null, t._scenario.referrer_policy);
+        invoker(t._subresourceUrl, callback, null, t._scenario.referrer_policy, test);
       }
 
     },
 
     start: function() {
       t._constructSubresourceUrl();
       t._constructExpectedReferrerUrl();
 
@@ -111,15 +113,15 @@ function ReferrerPolicyTestCase(scenario
                         t._scenario.referrer_url + "'.");
           assert_equals(result.headers.referer,
                         t._expectedReferrerUrl,
                         "Reported Referrer URL from HTTP header is '" +
                         t._expectedReferrerUrl + "'");
         }, "Reported Referrer URL is as expected: " + t._scenario.referrer_url);
 
         test.done();
-      })
+      }, test);
 
     }
   }
 
   return t;
 }