diff --git a/tests/wpt/metadata/MANIFEST.json b/tests/wpt/metadata/MANIFEST.json
index e3a1ebe61ed..24650ba5d95 100644
--- a/tests/wpt/metadata/MANIFEST.json
+++ b/tests/wpt/metadata/MANIFEST.json
@@ -650073,67 +650073,67 @@
    "support"
   ],
   "referrer-policy/css-integration/child-css/external-import-stylesheet.html": [
-   "a2d3e8ced0412b97422847d4d81c1403cf9ae52c",
+   "40f4234ad48d19162cefae933fd0f53a72ff0c19",
    "testharness"
   ],
   "referrer-policy/css-integration/child-css/internal-import-stylesheet.html": [
-   "aebf5031484b799989d6b6a9dd72a5bc28575214",
+   "30c5ea2903094af38dea9a7a565255d178069178",
    "testharness"
   ],
   "referrer-policy/css-integration/child-css/processing-instruction.html": [
-   "b6333e2c7b248c3f3b863bd06f1c99abd472f162",
+   "52a0ded42a185ed5ff6f449879e0ce50f8255868",
    "testharness"
   ],
   "referrer-policy/css-integration/css-test-helper.js": [
-   "f5886dbbcbe358438dfbac45c5a0127e9e990ad4",
+   "788df16a456b83a23de662b710c200042a1e7254",
    "support"
   ],
   "referrer-policy/css-integration/font-face/external-import-stylesheet.html": [
-   "c344c56c5bf322f35e8d8c74427d80391e6637d3",
+   "80e3587ad62f040f2cfb28645437fcbc0e66b415",
    "testharness"
   ],
   "referrer-policy/css-integration/font-face/external-stylesheet.html": [
-   "24e4bb99900a556cb0b44144a25c9f8249224eb7",
+   "a91eb3fe758299229040466deb2d1b0263f77197",
    "testharness"
   ],
   "referrer-policy/css-integration/font-face/internal-import-stylesheet.html": [
-   "54e2383423cab8679635d05c256c32e27a94c024",
+   "a637082a4ce7dff612b223fc8a4c2195db300013",
    "testharness"
   ],
   "referrer-policy/css-integration/font-face/internal-stylesheet.html": [
-   "b3869bcebdcdadea3e50d7e8713c853d46ba4816",
+   "eebd864bc56725b79c1f29c0597466574e2af091",
    "testharness"
   ],
   "referrer-policy/css-integration/font-face/processing-instruction.html": [
-   "89ee918e24e14b8ea5d35a7dfaf09610eb89ee11",
+   "bfc42d9fcbe355514c7bf72ac087d7159439824e",
    "testharness"
   ],
   "referrer-policy/css-integration/image/external-import-stylesheet.html": [
-   "0023af31b17ee883e6e9fe6cdd8f09b8eacf83d1",
+   "80c71b0e215b547d664aee8757d70188c012a9c0",
    "testharness"
   ],
   "referrer-policy/css-integration/image/external-stylesheet.html": [
-   "d14769db4a1221bb6e220aa594c4a3b6bab97aa1",
+   "ba7497b97de6911c149b423bf25305123e97150e",
    "testharness"
   ],
   "referrer-policy/css-integration/image/inline-style.html": [
-   "42128ae062093c0e8feb5d90ab62a6cb281cf8e9",
+   "758b6d91852f67d4e47726815804a5e366fe534d",
    "testharness"
   ],
   "referrer-policy/css-integration/image/internal-import-stylesheet.html": [
-   "90003547f4d4e2048cc33f7125d756d42507140d",
+   "24aa1858304a2130624589b0a64c6f9ec9cac5a1",
    "testharness"
   ],
   "referrer-policy/css-integration/image/internal-stylesheet.html": [
-   "943108d66e4b273a6d3be30b2ea8a0edb0490c7b",
+   "f4567885e1f1e215487a11f1023d117517cd88b8",
    "testharness"
   ],
   "referrer-policy/css-integration/image/presentation-attribute.html": [
-   "78401d3ec16866f1e51618bdb5cb028f5eea8490",
+   "d0a4d96f84c8e48ea5daf5699c7b04bbc877ba86",
    "testharness"
   ],
   "referrer-policy/css-integration/image/processing-instruction.html": [
-   "1ca18547dd54c4707250f400999a041f16f77ddf",
+   "926147be489a85164758dcf644c715e4a5c02de6",
    "testharness"
   ],
   "referrer-policy/css-integration/svg/external-stylesheet.html": [
@@ -650157,7 +650157,7 @@
    "testharness"
   ],
   "referrer-policy/generic/common.js": [
-   "f9bbe42b914c46822ec8b74aacd849789723dd72",
+   "a16691bccb2543ad68b81e9a16fa261d3cce6a9f",
    "support"
   ],
   "referrer-policy/generic/iframe-inheritance.html": [
@@ -650209,11 +650209,11 @@
    "support"
   ],
   "referrer-policy/generic/referrer-policy-test-case.js": [
-   "4641683cd850da86279dcd062aaf868d346aa2bd",
+   "2385cc2a1c4e51a2855299e42b69ac12362cd699",
    "support"
   ],
   "referrer-policy/generic/sandboxed-iframe-with-opaque-origin.html": [
-   "8fee77f836378ec137c3bf0d554f4def83a5caba",
+   "1b2b12bf6910e075338462de577dc4228f52a21f",
    "testharness"
   ],
   "referrer-policy/generic/sanity-checker.js": [
@@ -650221,7 +650221,7 @@
    "support"
   ],
   "referrer-policy/generic/subresource-test/area-navigate.html": [
-   "bca7e479fa2ca41505bc73cf74c6e518efa7e947",
+   "3eb824521b7801c518a7b36218075eb3d74bd639",
    "testharness"
   ],
   "referrer-policy/generic/subresource-test/attr-referrer-invalid-value.html": [
@@ -650229,31 +650229,31 @@
    "testharness"
   ],
   "referrer-policy/generic/subresource-test/fetch-messaging.html": [
-   "046b29e9a3e94753c1a552732b0f44d2883a011d",
+   "edb159d9eb1cf5eed6af249a40f70d9ecd079d68",
    "testharness"
   ],
   "referrer-policy/generic/subresource-test/iframe-messaging.html": [
-   "a3e55707c26f95624baaa54b8778d641cd756d72",
+   "606e18b281f6c3498573dc9bfaefefca1390026a",
    "testharness"
   ],
   "referrer-policy/generic/subresource-test/image-decoding.html": [
-   "448f12b1348fa77aaaebd52b2c3ee6ae9c73a5f6",
+   "9c50ea6619389dad8ad81c4c2afbeb8030b176db",
    "testharness"
   ],
   "referrer-policy/generic/subresource-test/link-navigate.html": [
-   "45e502004d4b640d0b2194e48d060b8d3cc3f120",
+   "95582f65bac8a3b478cc8cd4fe9b883fb507237f",
    "testharness"
   ],
   "referrer-policy/generic/subresource-test/script-messaging.html": [
-   "09c5db6193fed52c60edc2526609c3d501c45da8",
+   "f73f4406df20694480f82570ed8674fe283ea375",
    "testharness"
   ],
   "referrer-policy/generic/subresource-test/worker-messaging.html": [
-   "6d34366b943ad2b3b15f08179a58ef5227c675d0",
+   "fd7591882e91e7265fd740b9018248d21f13b5b9",
    "testharness"
   ],
   "referrer-policy/generic/subresource-test/xhr-messaging.html": [
-   "09f69140098a16bd66a117cf6187fedc862d9233",
+   "6ef4a9cfd4b98c3562fe7ef6e04eb931073166de",
    "testharness"
   ],
   "referrer-policy/generic/subresource/__init__.py": [
@@ -650381,7 +650381,7 @@
    "support"
   ],
   "referrer-policy/generic/unsupported-csp-referrer-directive.html": [
-   "9627d16559903b5202f842f3c3355a2e7005f65c",
+   "475efa55091778e747fa36030f7b422b89d6d4b9",
    "testharness"
   ],
   "referrer-policy/no-referrer-when-downgrade/attr-referrer/cross-origin/http-http/a-tag/no-redirect/insecure-protocol.http.html": [
diff --git a/tests/wpt/metadata/referrer-policy/generic/unsupported-csp-referrer-directive.html.ini b/tests/wpt/metadata/referrer-policy/generic/unsupported-csp-referrer-directive.html.ini
deleted file mode 100644
index c2b0313db96..00000000000
--- a/tests/wpt/metadata/referrer-policy/generic/unsupported-csp-referrer-directive.html.ini
+++ /dev/null
@@ -1,3 +0,0 @@
-[unsupported-csp-referrer-directive.html]
-  type: testharness
-  disabled: https://github.com/servo/servo/issues/4767
diff --git a/tests/wpt/web-platform-tests/referrer-policy/css-integration/child-css/external-import-stylesheet.html b/tests/wpt/web-platform-tests/referrer-policy/css-integration/child-css/external-import-stylesheet.html
index a2d3e8ced04..40f4234ad48 100644
--- a/tests/wpt/web-platform-tests/referrer-policy/css-integration/child-css/external-import-stylesheet.html
+++ b/tests/wpt/web-platform-tests/referrer-policy/css-integration/child-css/external-import-stylesheet.html
@@ -16,31 +16,29 @@
     <div class="styled"></div>
 
     <script>
-      let css_test = async_test("Child css from external stylesheet.");
-      let id = token();
-      let url_prefix = location.protocol + "//www1." + location.hostname + ":" + location.port;
-      let css_url = url_prefix +
-        "/referrer-policy/generic/subresource/stylesheet.py?id=" + id +
-        "&import-rule" + "&referrer-policy=no-referrer";
-      let check_url = url_prefix + "/referrer-policy/generic/subresource/stylesheet.py" +
-                      "?id=" + id + "&report-headers";
+      async_test(function(css_test) {
+        let id = token();
+        let url_prefix = location.protocol + "//www1." + location.hostname + ":" + location.port;
+        let css_url = url_prefix +
+          "/referrer-policy/generic/subresource/stylesheet.py?id=" + id +
+          "&import-rule" + "&referrer-policy=no-referrer";
+        let check_url = url_prefix + "/referrer-policy/generic/subresource/stylesheet.py" +
+                        "?id=" + id + "&report-headers";
 
-      let link = document.createElement("link");
-      link.href = css_url;
-      link.rel = "stylesheet";
-      link.onload = function() {
-        css_test.step_timeout(
-            queryXhr.bind(this, check_url,
-                          function(message) {
-                            css_test.step(function() {
-                              assert_own_property(message, "headers");
-                              assert_equals(message.referrer, undefined);
-                            });
-                            css_test.done();
-                          }),
-            1000);
-      };
-      document.head.appendChild(link);
+        let link = document.createElement("link");
+        link.href = css_url;
+        link.rel = "stylesheet";
+        link.onload = function() {
+          css_test.step_timeout(function() {
+              queryXhr(check_url, function(message) {
+                  assert_own_property(message, "headers");
+                  assert_equals(message.referrer, undefined);
+                  css_test.done();
+              }, null, null, css_test);
+          }, 1000);
+        };
+        document.head.appendChild(link);
+      }, "Child css from external stylesheet.");
     </script>
 
     <div id="log"></div>
diff --git a/tests/wpt/web-platform-tests/referrer-policy/css-integration/child-css/internal-import-stylesheet.html b/tests/wpt/web-platform-tests/referrer-policy/css-integration/child-css/internal-import-stylesheet.html
index aebf5031484..30c5ea29030 100644
--- a/tests/wpt/web-platform-tests/referrer-policy/css-integration/child-css/internal-import-stylesheet.html
+++ b/tests/wpt/web-platform-tests/referrer-policy/css-integration/child-css/internal-import-stylesheet.html
@@ -16,28 +16,26 @@
     <div class="styled"></div>
 
     <script>
-      let css_test = async_test("Child css from internal stylesheet.");
-      let id = token();
-      let url_prefix = location.protocol + "//www1." + location.hostname + ":" + location.port;
-      let css_url = url_prefix + "/referrer-policy/generic/subresource/stylesheet.py?id=" + id + "&import-rule";
-      let check_url = url_prefix + "/referrer-policy/generic/subresource/stylesheet.py" +
-                      "?id=" + id + "&report-headers";
+      async_test(function(css_test) {
+        let id = token();
+        let url_prefix = location.protocol + "//www1." + location.hostname + ":" + location.port;
+        let css_url = url_prefix + "/referrer-policy/generic/subresource/stylesheet.py?id=" + id + "&import-rule";
+        let check_url = url_prefix + "/referrer-policy/generic/subresource/stylesheet.py" +
+                        "?id=" + id + "&report-headers";
 
-      let style = document.createElement("style");
-      style.type = 'text/css';
-      style.appendChild(document.createTextNode("@import url('" + css_url + "');"));
-      document.head.appendChild(style);
-      css_test.step_timeout(
-        queryXhr.bind(this, check_url,
-                      function(message) {
-                        css_test.step(function() {
-                          assert_own_property(message, "headers");
-                          assert_own_property(message, "referrer");
-                          assert_equals(message.referrer, css_url);
-                        });
-                        css_test.done();
-                      }),
-        1000);
+        let style = document.createElement("style");
+        style.type = 'text/css';
+        style.appendChild(document.createTextNode("@import url('" + css_url + "');"));
+        document.head.appendChild(style);
+        css_test.step_timeout(function() {
+          queryXhr(check_url, function(message) {
+              assert_own_property(message, "headers");
+              assert_own_property(message, "referrer");
+              assert_equals(message.referrer, css_url);
+              css_test.done();
+          }, null, null, css_test);
+        }, 1000);
+      }, "Child css from internal stylesheet.");
     </script>
 
     <div id="log"></div>
diff --git a/tests/wpt/web-platform-tests/referrer-policy/css-integration/child-css/processing-instruction.html b/tests/wpt/web-platform-tests/referrer-policy/css-integration/child-css/processing-instruction.html
index b6333e2c7b2..52a0ded42a1 100644
--- a/tests/wpt/web-platform-tests/referrer-policy/css-integration/child-css/processing-instruction.html
+++ b/tests/wpt/web-platform-tests/referrer-policy/css-integration/child-css/processing-instruction.html
@@ -15,31 +15,29 @@
     <div class="styled"></div>
 
     <script>
-      let css_test = async_test("Child css via a ProcessingInstruction.");
-      let id = token();
-      let url_prefix = location.protocol + "//www1." + location.hostname + ":" +
-                       location.port +
-                       "/referrer-policy/generic/subresource/stylesheet.py?id=" +
-                       id;
-      let css_url = url_prefix + "&amp;import-rule";
-      let expected = url_prefix + "&import-rule";
-      let check_url = url_prefix + "&report-headers";
+      async_test(function(css_test) {
+        let id = token();
+        let url_prefix = location.protocol + "//www1." + location.hostname + ":" +
+                         location.port +
+                         "/referrer-policy/generic/subresource/stylesheet.py?id=" +
+                         id;
+        let css_url = url_prefix + "&amp;import-rule";
+        let expected = url_prefix + "&import-rule";
+        let check_url = url_prefix + "&report-headers";
 
-      let processingInstruction =
-        document.createProcessingInstruction(
-          "xml-stylesheet", "href=\"" +css_url + "\" type=\"text/css\"");
-      css_test.step_timeout(
-          queryXhr.bind(this, check_url,
-                        function(message) {
-                          css_test.step(function() {
-                            assert_own_property(message, "headers");
-                            assert_own_property(message, "referrer");
-                            assert_equals(message.referrer, expected);
-                          });
-                          css_test.done();
-                        }),
-          1000);
-      document.insertBefore(processingInstruction, document.firstChild);
+        let processingInstruction =
+          document.createProcessingInstruction(
+            "xml-stylesheet", "href=\"" +css_url + "\" type=\"text/css\"");
+        css_test.step_timeout(function() {
+            queryXhr(check_url, function(message) {
+                assert_own_property(message, "headers");
+                assert_own_property(message, "referrer");
+                assert_equals(message.referrer, expected);
+                css_test.done();
+            }, null, null, css_test);
+        }, 1000);
+        document.insertBefore(processingInstruction, document.firstChild);
+      }, "Child css via a ProcessingInstruction.");
     </script>
 
     <div id="log"></div>
diff --git a/tests/wpt/web-platform-tests/referrer-policy/css-integration/css-test-helper.js b/tests/wpt/web-platform-tests/referrer-policy/css-integration/css-test-helper.js
index f5886dbbcbe..788df16a456 100644
--- a/tests/wpt/web-platform-tests/referrer-policy/css-integration/css-test-helper.js
+++ b/tests/wpt/web-platform-tests/referrer-policy/css-integration/css-test-helper.js
@@ -33,22 +33,18 @@ function runSvgTests(testProperties, testDescription, testFunction) {
       property: property,
     };
 
-    testFunction(current);
+    current.test.step(function() { testFunction(current) });
 
     let check_url = url_prefix + "svg.py" + "?id=" + current.id +
                     "&report-headers";
-    current.test.step_timeout(
-      queryXhr.bind(this, check_url,
-                    function(message) {
-                      current.test.step(function() {
-                        assert_own_property(message, "headers");
-                        assert_own_property(message, "referrer");
-                        assert_equals(message.referrer, current.expected);
-                      });
-                      current.test.done();
-                    }),
-      800);
-
+    current.test.step_timeout(function() {
+      queryXhr(check_url, function(message) {
+          assert_own_property(message, "headers");
+          assert_own_property(message, "referrer");
+          assert_equals(message.referrer, current.expected);
+          current.test.done();
+      }, null, null, current.test);
+    }, 800);
   };
 
   add_result_callback(runNextTest);
diff --git a/tests/wpt/web-platform-tests/referrer-policy/css-integration/font-face/external-import-stylesheet.html b/tests/wpt/web-platform-tests/referrer-policy/css-integration/font-face/external-import-stylesheet.html
index c344c56c5bf..80e3587ad62 100644
--- a/tests/wpt/web-platform-tests/referrer-policy/css-integration/font-face/external-import-stylesheet.html
+++ b/tests/wpt/web-platform-tests/referrer-policy/css-integration/font-face/external-import-stylesheet.html
@@ -17,35 +17,33 @@
     <div class="styled"></div>
 
     <script>
-      let css_test = async_test("Font from imported stylesheet (external).");
-      let id = token();
-      let css_url = location.protocol + "//www1." + location.hostname + ":" +
-        location.port +
-        "/referrer-policy/generic/subresource/stylesheet.py?id=" + id +
-        "&import-rule" + "&type=font";
-      let url_prefix = location.protocol + "//" + location.hostname + ":" + location.port;
-      let css_referrer = url_prefix +
-        "/referrer-policy/generic/subresource/stylesheet.py?id=" + id + "&type=font";
-      let font_url = url_prefix + "/referrer-policy/generic/subresource/font.py" +
-                     "?id=" + id + "&report-headers" + "&type=font";
+      async_test(function(css_test) {
+        let id = token();
+        let css_url = location.protocol + "//www1." + location.hostname + ":" +
+          location.port +
+          "/referrer-policy/generic/subresource/stylesheet.py?id=" + id +
+          "&import-rule" + "&type=font";
+        let url_prefix = location.protocol + "//" + location.hostname + ":" + location.port;
+        let css_referrer = url_prefix +
+          "/referrer-policy/generic/subresource/stylesheet.py?id=" + id + "&type=font";
+        let font_url = url_prefix + "/referrer-policy/generic/subresource/font.py" +
+                       "?id=" + id + "&report-headers" + "&type=font";
 
-      let link = document.createElement("link");
-      link.href = css_url;
-      link.rel = "stylesheet";
-      link.onload = function() {
-        css_test.step_timeout(
-            queryXhr.bind(this, font_url,
-                          function(message) {
-                            css_test.step(function() {
-                              assert_own_property(message, "headers");
-                              assert_own_property(message, "referrer");
-                              assert_equals(message.referrer, css_referrer);
-                            });
-                            css_test.done();
-                          }),
-            1000);
-      };
-      document.head.appendChild(link);
+        let link = document.createElement("link");
+        link.href = css_url;
+        link.rel = "stylesheet";
+        link.onload = function() {
+          css_test.step_timeout(function() {
+              queryXhr(font_url, function(message) {
+                  assert_own_property(message, "headers");
+                  assert_own_property(message, "referrer");
+                  assert_equals(message.referrer, css_referrer);
+                  css_test.done();
+              }, null, null, css_test);
+          }, 1000);
+        };
+        document.head.appendChild(link);
+      }, "Font from imported stylesheet (external).");
     </script>
 
     <div id="log"></div>
diff --git a/tests/wpt/web-platform-tests/referrer-policy/css-integration/font-face/external-stylesheet.html b/tests/wpt/web-platform-tests/referrer-policy/css-integration/font-face/external-stylesheet.html
index 24e4bb99900..a91eb3fe758 100644
--- a/tests/wpt/web-platform-tests/referrer-policy/css-integration/font-face/external-stylesheet.html
+++ b/tests/wpt/web-platform-tests/referrer-policy/css-integration/font-face/external-stylesheet.html
@@ -16,30 +16,28 @@
     <div class="styled"></div>
 
     <script>
-      let css_test = async_test("Font from external stylesheet.");
-      let id = token();
-      let url_prefix = location.protocol + "//www1." + location.hostname + ":" + location.port;
-      let css_url = url_prefix + "/referrer-policy/generic/subresource/stylesheet.py?id=" + id + "&type=font";
-      let font_url = url_prefix + "/referrer-policy/generic/subresource/font.py" +
-                    "?id=" + id + "&report-headers";
+      async_test(function(css_test) {
+        let id = token();
+        let url_prefix = location.protocol + "//www1." + location.hostname + ":" + location.port;
+        let css_url = url_prefix + "/referrer-policy/generic/subresource/stylesheet.py?id=" + id + "&type=font";
+        let font_url = url_prefix + "/referrer-policy/generic/subresource/font.py" +
+                      "?id=" + id + "&report-headers";
 
-      let link = document.createElement("link");
-      link.href = css_url;
-      link.rel = "stylesheet";
-      link.onload = function() {
-        css_test.step_timeout(
-            queryXhr.bind(this, font_url,
-                          function(message) {
-                            css_test.step(function() {
-                              assert_own_property(message, "headers");
-                              assert_own_property(message, "referrer");
-                              assert_equals(message.referrer, css_url);
-                            });
-                            css_test.done();
-                          }),
-            1000);
-      };
-      document.head.appendChild(link);
+        let link = document.createElement("link");
+        link.href = css_url;
+        link.rel = "stylesheet";
+        link.onload = function() {
+          css_test.step_timeout(function() {
+              queryXhr(font_url, function(message) {
+                  assert_own_property(message, "headers");
+                  assert_own_property(message, "referrer");
+                  assert_equals(message.referrer, css_url);
+                  css_test.done();
+              }, null, null, css_test);
+          }, 1000);
+        };
+        document.head.appendChild(link);
+      }, "Font from external stylesheet.");
     </script>
 
     <div id="log"></div>
diff --git a/tests/wpt/web-platform-tests/referrer-policy/css-integration/font-face/internal-import-stylesheet.html b/tests/wpt/web-platform-tests/referrer-policy/css-integration/font-face/internal-import-stylesheet.html
index 54e2383423c..a637082a4ce 100644
--- a/tests/wpt/web-platform-tests/referrer-policy/css-integration/font-face/internal-import-stylesheet.html
+++ b/tests/wpt/web-platform-tests/referrer-policy/css-integration/font-face/internal-import-stylesheet.html
@@ -17,28 +17,26 @@
     <div class="styled"></div>
 
     <script>
-      let css_test = async_test("Font from imported stylesheet (internal).");
-      let id = token();
-      let url_prefix = location.protocol + "//www1." + location.hostname + ":" +
-                       location.port + "/referrer-policy/generic/subresource/";
-      let css_url = url_prefix + "stylesheet.py?id=" + id + "&type=font";
-      let font_url = url_prefix + "font.py?report-headers&id=" + id;
+      async_test(function(css_test) {
+        let id = token();
+        let url_prefix = location.protocol + "//www1." + location.hostname + ":" +
+                         location.port + "/referrer-policy/generic/subresource/";
+        let css_url = url_prefix + "stylesheet.py?id=" + id + "&type=font";
+        let font_url = url_prefix + "font.py?report-headers&id=" + id;
 
-      let style = document.createElement("style");
-      style.textContent = "@import url('" + css_url + "');";
-      document.head.appendChild(style);
-      css_test.step_timeout(
-          queryXhr.bind(this, font_url,
-                        function(message) {
-                          css_test.step(function() {
-                            assert_own_property(message, "headers");
-                            assert_own_property(message, "referrer");
-                            assert_equals(message.referrer, css_url);
-                          });
-                          css_test.done();
-                        }),
-          1000);
-      </script>
+        let style = document.createElement("style");
+        style.textContent = "@import url('" + css_url + "');";
+        document.head.appendChild(style);
+        css_test.step_timeout(function() {
+            queryXhr(font_url, function(message) {
+                assert_own_property(message, "headers");
+                assert_own_property(message, "referrer");
+                assert_equals(message.referrer, css_url);
+                css_test.done();
+            }, null, null, css_test);
+        }, 1000);
+      }, "Font from imported stylesheet (internal).");
+    </script>
 
     <div id="log"></div>
   </body>
diff --git a/tests/wpt/web-platform-tests/referrer-policy/css-integration/font-face/internal-stylesheet.html b/tests/wpt/web-platform-tests/referrer-policy/css-integration/font-face/internal-stylesheet.html
index b3869bcebdc..eebd864bc56 100644
--- a/tests/wpt/web-platform-tests/referrer-policy/css-integration/font-face/internal-stylesheet.html
+++ b/tests/wpt/web-platform-tests/referrer-policy/css-integration/font-face/internal-stylesheet.html
@@ -16,29 +16,27 @@
     <div class="styled"></div>
 
     <script>
-      let css_test = async_test("Font from internal stylesheet.");
-      let id = token();
-      let css_url = location.protocol + "//www1." + location.hostname + ":" +
-                    location.port +
-                    "/referrer-policy/generic/subresource/font.py" + "?id=" +
-                    id + "&type=font";
-      let font_url = css_url + "&report-headers";
+      async_test(function(css_test) {
+        let id = token();
+        let css_url = location.protocol + "//www1." + location.hostname + ":" +
+                      location.port +
+                      "/referrer-policy/generic/subresource/font.py" + "?id=" +
+                      id + "&type=font";
+        let font_url = css_url + "&report-headers";
 
-      let style = document.createElement("style");
-      style.textContent = "@font-face { font-family: 'wpt'; font-style: normal; font-weight: normal; src: url(" + css_url + "); format('truetype'); } body { font-family: 'wpt';}";
-      document.head.appendChild(style);
-      css_test.step_timeout(
-          queryXhr.bind(this, font_url,
-                        function(message) {
-                          css_test.step(function() {
-                            assert_own_property(message, "headers");
-                            assert_own_property(message, "referrer");
-                            assert_equals(message.referrer, location.origin + "/");
-                          });
-                          css_test.done();
-                        }),
-          1000);
-      </script>
+        let style = document.createElement("style");
+        style.textContent = "@font-face { font-family: 'wpt'; font-style: normal; font-weight: normal; src: url(" + css_url + "); format('truetype'); } body { font-family: 'wpt';}";
+        document.head.appendChild(style);
+        css_test.step_timeout(function() {
+            queryXhr(font_url, function(message) {
+                assert_own_property(message, "headers");
+                assert_own_property(message, "referrer");
+                assert_equals(message.referrer, location.origin + "/");
+                css_test.done();
+            }, null, null, css_test);
+        }, 1000);
+      }, "Font from internal stylesheet.");
+    </script>
 
     <div id="log"></div>
   </body>
diff --git a/tests/wpt/web-platform-tests/referrer-policy/css-integration/font-face/processing-instruction.html b/tests/wpt/web-platform-tests/referrer-policy/css-integration/font-face/processing-instruction.html
index 89ee918e24e..bfc42d9fcbe 100644
--- a/tests/wpt/web-platform-tests/referrer-policy/css-integration/font-face/processing-instruction.html
+++ b/tests/wpt/web-platform-tests/referrer-policy/css-integration/font-face/processing-instruction.html
@@ -17,33 +17,31 @@
     <div class="styled"></div>
 
     <script>
-      let css_test = async_test("Font from external stylesheet (from ProcessingInstruction).");
-      let id = token();
-      let url_prefix = location.protocol + "//www1." + location.hostname + ":" + location.port;
-      let css_url = url_prefix +
-                    "/referrer-policy/generic/subresource/stylesheet.py?id=" +
-                    id + "&amp;type=font";
-      let expected = url_prefix +
-                    "/referrer-policy/generic/subresource/stylesheet.py?id=" +
-                    id + "&type=font";
-      let font_url = url_prefix + "/referrer-policy/generic/subresource/font.py" +
-                     "?id=" + id + "&report-headers";
+      async_test(function(css_test) {
+        let id = token();
+        let url_prefix = location.protocol + "//www1." + location.hostname + ":" + location.port;
+        let css_url = url_prefix +
+                      "/referrer-policy/generic/subresource/stylesheet.py?id=" +
+                      id + "&amp;type=font";
+        let expected = url_prefix +
+                      "/referrer-policy/generic/subresource/stylesheet.py?id=" +
+                      id + "&type=font";
+        let font_url = url_prefix + "/referrer-policy/generic/subresource/font.py" +
+                       "?id=" + id + "&report-headers";
 
-      let processingInstruction =
-        document.createProcessingInstruction(
-          "xml-stylesheet", "href=\"" + css_url + "\" type=\"text/css\"");
-      css_test.step_timeout(
-          queryXhr.bind(this, font_url,
-                        function(message) {
-                          css_test.step(function() {
-                            assert_own_property(message, "headers");
-                            assert_own_property(message, "referrer");
-                            assert_equals(message.referrer, expected);
-                          });
-                          css_test.done();
-                        }),
-          1000);
-      document.insertBefore(processingInstruction, document.firstChild);
+        let processingInstruction =
+          document.createProcessingInstruction(
+            "xml-stylesheet", "href=\"" + css_url + "\" type=\"text/css\"");
+        css_test.step_timeout(function() {
+            queryXhr(font_url, function(message) {
+                assert_own_property(message, "headers");
+                assert_own_property(message, "referrer");
+                assert_equals(message.referrer, expected);
+                css_test.done();
+            }, null, null, css_test);
+        }, 1000);
+        document.insertBefore(processingInstruction, document.firstChild);
+      }, "Font from external stylesheet (from ProcessingInstruction).");
     </script>
 
     <div id="log"></div>
diff --git a/tests/wpt/web-platform-tests/referrer-policy/css-integration/image/external-import-stylesheet.html b/tests/wpt/web-platform-tests/referrer-policy/css-integration/image/external-import-stylesheet.html
index 0023af31b17..80c71b0e215 100644
--- a/tests/wpt/web-platform-tests/referrer-policy/css-integration/image/external-import-stylesheet.html
+++ b/tests/wpt/web-platform-tests/referrer-policy/css-integration/image/external-import-stylesheet.html
@@ -17,35 +17,33 @@
     <div class="styled"></div>
 
     <script>
-      var css_test = async_test("Image from imported stylesheet (external).");
-      var id = token();
-      var css_url = location.protocol + "//www1." + location.hostname + ":" + location.port +
-        "/referrer-policy/generic/subresource/stylesheet.py?id=" + id +
-        "&import-rule" + "&type=image";
-      var url_prefix = location.protocol + "//" + location.hostname + ":" + location.port;
-      var css_referrer = url_prefix +
-        "/referrer-policy/generic/subresource/stylesheet.py?id=" + id +
-        "&type=image";
-      var img_url = url_prefix + "/referrer-policy/generic/subresource/image.py" +
-                    "?id=" + id + "&report-headers";
+      async_test(function(css_test) {
+        var id = token();
+        var css_url = location.protocol + "//www1." + location.hostname + ":" + location.port +
+          "/referrer-policy/generic/subresource/stylesheet.py?id=" + id +
+          "&import-rule" + "&type=image";
+        var url_prefix = location.protocol + "//" + location.hostname + ":" + location.port;
+        var css_referrer = url_prefix +
+          "/referrer-policy/generic/subresource/stylesheet.py?id=" + id +
+          "&type=image";
+        var img_url = url_prefix + "/referrer-policy/generic/subresource/image.py" +
+                      "?id=" + id + "&report-headers";
 
-      var link = document.createElement("link");
-      link.href = css_url;
-      link.rel = "stylesheet";
-      link.onload = function() {
-        css_test.step_timeout(
-            queryXhr.bind(this, img_url,
-                          function(message) {
-                            css_test.step(function() {
-                              assert_own_property(message, "headers");
-                              assert_own_property(message, "referrer");
-                              assert_equals(message.referrer, css_referrer);
-                            });
-                            css_test.done();
-                          }),
-            1000);
-      };
-      document.head.appendChild(link);
+        var link = document.createElement("link");
+        link.href = css_url;
+        link.rel = "stylesheet";
+        link.onload = function() {
+          css_test.step_timeout(function() {
+              queryXhr(img_url, function(message) {
+                  assert_own_property(message, "headers");
+                  assert_own_property(message, "referrer");
+                  assert_equals(message.referrer, css_referrer);
+                  css_test.done();
+               }, null, null, css_test);
+          }, 1000);
+        };
+        document.head.appendChild(link);
+      }, "Image from imported stylesheet (external).");
     </script>
 
     <div id="log"></div>
diff --git a/tests/wpt/web-platform-tests/referrer-policy/css-integration/image/external-stylesheet.html b/tests/wpt/web-platform-tests/referrer-policy/css-integration/image/external-stylesheet.html
index d14769db4a1..ba7497b97de 100644
--- a/tests/wpt/web-platform-tests/referrer-policy/css-integration/image/external-stylesheet.html
+++ b/tests/wpt/web-platform-tests/referrer-policy/css-integration/image/external-stylesheet.html
@@ -16,30 +16,28 @@
     <div class="styled"></div>
 
     <script>
-      var css_test = async_test("Image from external stylesheet.");
-      var id = token();
-      var url_prefix = location.protocol + "//www1." + location.hostname + ":" + location.port;
-      var css_url = url_prefix + "/referrer-policy/generic/subresource/stylesheet.py?id=" + id;
-      var img_url = url_prefix + "/referrer-policy/generic/subresource/image.py" +
-                    "?id=" + id + "&report-headers";
+      async_test(function(css_test) {
+        var id = token();
+        var url_prefix = location.protocol + "//www1." + location.hostname + ":" + location.port;
+        var css_url = url_prefix + "/referrer-policy/generic/subresource/stylesheet.py?id=" + id;
+        var img_url = url_prefix + "/referrer-policy/generic/subresource/image.py" +
+                      "?id=" + id + "&report-headers";
 
-      var link = document.createElement("link");
-      link.href = css_url;
-      link.rel = "stylesheet";
-      link.onload = function() {
-        css_test.step_timeout(
-            queryXhr.bind(this, img_url,
-                          function(message) {
-                            css_test.step(function() {
-                              assert_own_property(message, "headers");
-                              assert_own_property(message, "referrer");
-                              assert_equals(message.referrer, css_url);
-                            });
-                            css_test.done();
-                          }),
-            1000);
-      };
-      document.head.appendChild(link);
+        var link = document.createElement("link");
+        link.href = css_url;
+        link.rel = "stylesheet";
+        link.onload = css_test.step_func(function() {
+          css_test.step_timeout(function() {
+              queryXhr(img_url, function(message) {
+                  assert_own_property(message, "headers");
+                  assert_own_property(message, "referrer");
+                  assert_equals(message.referrer, css_url);
+                  css_test.done();
+              }, null, null, css_test);
+          }, 1000);
+        });
+        document.head.appendChild(link);
+      }, "Image from external stylesheet.");
     </script>
 
     <div id="log"></div>
diff --git a/tests/wpt/web-platform-tests/referrer-policy/css-integration/image/inline-style.html b/tests/wpt/web-platform-tests/referrer-policy/css-integration/image/inline-style.html
index 42128ae0620..758b6d91852 100644
--- a/tests/wpt/web-platform-tests/referrer-policy/css-integration/image/inline-style.html
+++ b/tests/wpt/web-platform-tests/referrer-policy/css-integration/image/inline-style.html
@@ -16,25 +16,23 @@
     <div class="styled"></div>
 
     <script>
-      var css_test = async_test("Image from inline styles.");
-      var id = token();
-      var css_url = location.protocol + "//www1." + location.hostname + ":" + location.port + "/referrer-policy/generic/subresource/image.py" + "?id=" + id;
-      var img_url = css_url + "&report-headers";
+      async_test(function(css_test) {
+        var id = token();
+        var css_url = location.protocol + "//www1." + location.hostname + ":" + location.port + "/referrer-policy/generic/subresource/image.py" + "?id=" + id;
+        var img_url = css_url + "&report-headers";
 
-      var div = document.querySelector("div.styled");
-      div.style = "content:url(" + css_url + ")";
-      css_test.step_timeout(
-          queryXhr.bind(this, img_url,
-                        function(message) {
-                          css_test.step(function() {
-                            assert_own_property(message, "headers");
-                            assert_own_property(message, "referrer");
-                            assert_equals(message.referrer, location.origin + "/");
-                          });
-                          css_test.done();
-                        }),
-          1000);
-      </script>
+        var div = document.querySelector("div.styled");
+        div.style = "content:url(" + css_url + ")";
+        css_test.step_timeout(function() {
+            queryXhr(img_url, function(message) {
+                assert_own_property(message, "headers");
+                assert_own_property(message, "referrer");
+                assert_equals(message.referrer, location.origin + "/");
+                css_test.done();
+            }, null, null, css_test);
+        }, 1000);
+      }, "Image from inline styles.");
+    </script>
 
     <div id="log"></div>
   </body>
diff --git a/tests/wpt/web-platform-tests/referrer-policy/css-integration/image/internal-import-stylesheet.html b/tests/wpt/web-platform-tests/referrer-policy/css-integration/image/internal-import-stylesheet.html
index 90003547f4d..24aa1858304 100644
--- a/tests/wpt/web-platform-tests/referrer-policy/css-integration/image/internal-import-stylesheet.html
+++ b/tests/wpt/web-platform-tests/referrer-policy/css-integration/image/internal-import-stylesheet.html
@@ -17,28 +17,26 @@
     <div class="styled"></div>
 
     <script>
-      var css_test = async_test("Image from imported stylesheet (internal).");
-      var id = token();
-      var url_prefix =  location.protocol + "//www1." + location.hostname + ":" + location.port + "/referrer-policy/generic/subresource/";
-      var css_url = url_prefix + "stylesheet.py?id=" + id;
-      var img_url = url_prefix + "image.py?report-headers&id=" + id;
+      async_test(function(css_test) {
+        var id = token();
+        var url_prefix =  location.protocol + "//www1." + location.hostname + ":" + location.port + "/referrer-policy/generic/subresource/";
+        var css_url = url_prefix + "stylesheet.py?id=" + id;
+        var img_url = url_prefix + "image.py?report-headers&id=" + id;
 
-      var style = document.createElement("style");
-      style.type = 'text/css';
-      style.appendChild(document.createTextNode("@import url('" + css_url + "');"));
-      document.head.appendChild(style);
-      css_test.step_timeout(
-          queryXhr.bind(this, img_url,
-                        function(message) {
-                          css_test.step(function() {
-                            assert_own_property(message, "headers");
-                            assert_own_property(message, "referrer");
-                            assert_equals(message.referrer, css_url);
-                          });
-                          css_test.done();
-                        }),
-          1000);
-      </script>
+        var style = document.createElement("style");
+        style.type = 'text/css';
+        style.appendChild(document.createTextNode("@import url('" + css_url + "');"));
+        document.head.appendChild(style);
+        css_test.step_timeout(function() {
+            queryXhr(img_url, function(message) {
+                assert_own_property(message, "headers");
+                assert_own_property(message, "referrer");
+                assert_equals(message.referrer, css_url);
+                css_test.done();
+            }, null, null, css_test);
+        }, 1000);
+      }, "Image from imported stylesheet (internal).");
+    </script>
 
     <div id="log"></div>
   </body>
diff --git a/tests/wpt/web-platform-tests/referrer-policy/css-integration/image/internal-stylesheet.html b/tests/wpt/web-platform-tests/referrer-policy/css-integration/image/internal-stylesheet.html
index 943108d66e4..f4567885e1f 100644
--- a/tests/wpt/web-platform-tests/referrer-policy/css-integration/image/internal-stylesheet.html
+++ b/tests/wpt/web-platform-tests/referrer-policy/css-integration/image/internal-stylesheet.html
@@ -16,27 +16,25 @@
     <div class="styled"></div>
 
     <script>
-      var css_test = async_test("Image from internal stylesheet.");
-      var id = token();
-      var css_url = location.protocol + "//www1." + location.hostname + ":" + location.port + "/referrer-policy/generic/subresource/image.py" + "?id=" + id;
-      var img_url = css_url + "&report-headers";
+      async_test(function(css_test) {
+        var id = token();
+        var css_url = location.protocol + "//www1." + location.hostname + ":" + location.port + "/referrer-policy/generic/subresource/image.py" + "?id=" + id;
+        var img_url = css_url + "&report-headers";
 
-      var style = document.createElement("style");
-      style.type = 'text/css';
-      style.appendChild(document.createTextNode("div.styled::before { content:url(" + css_url + ")}"));
-      document.head.appendChild(style);
-      css_test.step_timeout(
-          queryXhr.bind(this, img_url,
-                        function(message) {
-                          css_test.step(function() {
-                            assert_own_property(message, "headers");
-                            assert_own_property(message, "referrer");
-                            assert_equals(message.referrer, location.origin + "/");
-                          });
-                          css_test.done();
-                        }),
-          1000);
-      </script>
+        var style = document.createElement("style");
+        style.type = 'text/css';
+        style.appendChild(document.createTextNode("div.styled::before { content:url(" + css_url + ")}"));
+        document.head.appendChild(style);
+        css_test.step_timeout(function() {
+          queryXhr(img_url, function(message) {
+            assert_own_property(message, "headers");
+            assert_own_property(message, "referrer");
+            assert_equals(message.referrer, location.origin + "/");
+            css_test.done();
+          }, null, null, css_test);
+        }, 1000);
+      }, "Image from internal stylesheet.");
+    </script>
 
     <div id="log"></div>
   </body>
diff --git a/tests/wpt/web-platform-tests/referrer-policy/css-integration/image/presentation-attribute.html b/tests/wpt/web-platform-tests/referrer-policy/css-integration/image/presentation-attribute.html
index 78401d3ec16..d0a4d96f84c 100644
--- a/tests/wpt/web-platform-tests/referrer-policy/css-integration/image/presentation-attribute.html
+++ b/tests/wpt/web-platform-tests/referrer-policy/css-integration/image/presentation-attribute.html
@@ -14,24 +14,22 @@
     the referrer and referrer policy from the document.</p>
 
     <script>
-      var css_test = async_test("Image from presentation attributes.");
-      var id = token();
-      var css_url = location.protocol + "//www1." + location.hostname + ":" + location.port + "/referrer-policy/generic/subresource/image.py" + "?id=" + id;
-      var img_url = css_url + "&report-headers";
+      async_test(function(css_test) {
+        var id = token();
+        var css_url = location.protocol + "//www1." + location.hostname + ":" + location.port + "/referrer-policy/generic/subresource/image.py" + "?id=" + id;
+        var img_url = css_url + "&report-headers";
 
-      document.body.background = css_url;
-      css_test.step_timeout(
-          queryXhr.bind(this, img_url,
-                        function(message) {
-                          css_test.step(function() {
-                            assert_own_property(message, "headers");
-                            assert_own_property(message, "referrer");
-                            assert_equals(message.referrer, location.origin + "/");
-                          });
-                          css_test.done();
-                        }),
-          1000);
-      </script>
+        document.body.background = css_url;
+        css_test.step_timeout(function() {
+            queryXhr(img_url, function(message) {
+                assert_own_property(message, "headers");
+                assert_own_property(message, "referrer");
+                assert_equals(message.referrer, location.origin + "/");
+                css_test.done();
+            }, null, null, css_test);
+        }, 1000);
+      }, "Image from presentation attributes.");
+    </script>
 
     <div id="log"></div>
   </body>
diff --git a/tests/wpt/web-platform-tests/referrer-policy/css-integration/image/processing-instruction.html b/tests/wpt/web-platform-tests/referrer-policy/css-integration/image/processing-instruction.html
index 1ca18547dd5..926147be489 100644
--- a/tests/wpt/web-platform-tests/referrer-policy/css-integration/image/processing-instruction.html
+++ b/tests/wpt/web-platform-tests/referrer-policy/css-integration/image/processing-instruction.html
@@ -17,26 +17,24 @@
     <div class="styled"></div>
 
     <script>
-      var css_test = async_test("Image from external stylesheet (from ProcessingInstruction).");
-      var id = token();
-      var url_prefix = location.protocol + "//www1." + location.hostname + ":" + location.port;
-      var css_url = url_prefix + "/referrer-policy/generic/subresource/stylesheet.py?id=" + id;
-      var img_url = url_prefix + "/referrer-policy/generic/subresource/image.py" +
-                    "?id=" + id + "&report-headers";
+      async_test(function(css_test) {
+        var id = token();
+        var url_prefix = location.protocol + "//www1." + location.hostname + ":" + location.port;
+        var css_url = url_prefix + "/referrer-policy/generic/subresource/stylesheet.py?id=" + id;
+        var img_url = url_prefix + "/referrer-policy/generic/subresource/image.py" +
+                      "?id=" + id + "&report-headers";
 
-      var processingInstruction = document.createProcessingInstruction("xml-stylesheet", "href=\"" + css_url + "\" type=\"text/css\"");
-      css_test.step_timeout(
-          queryXhr.bind(this, img_url,
-                        function(message) {
-                          css_test.step(function() {
-                            assert_own_property(message, "headers");
-                            assert_own_property(message, "referrer");
-                            assert_equals(message.referrer, css_url);
-                          });
-                          css_test.done();
-                        }),
-          1000);
-      document.insertBefore(processingInstruction, document.firstChild);
+        var processingInstruction = document.createProcessingInstruction("xml-stylesheet", "href=\"" + css_url + "\" type=\"text/css\"");
+        css_test.step_timeout(function() {
+            queryXhr(img_url, function(message) {
+                assert_own_property(message, "headers");
+                assert_own_property(message, "referrer");
+                assert_equals(message.referrer, css_url);
+                css_test.done();
+            }, null, null, css_test);
+        }, 1000);
+        document.insertBefore(processingInstruction, document.firstChild);
+      }, "Image from external stylesheet (from ProcessingInstruction).");
     </script>
 
     <div id="log"></div>
diff --git a/tests/wpt/web-platform-tests/referrer-policy/generic/common.js b/tests/wpt/web-platform-tests/referrer-policy/generic/common.js
index f9bbe42b914..a16691bccb2 100644
--- a/tests/wpt/web-platform-tests/referrer-policy/generic/common.js
+++ b/tests/wpt/web-platform-tests/referrer-policy/generic/common.js
@@ -99,15 +99,15 @@ function wrapResult(url, server_data) {
   }
 }
 
-function queryIframe(url, callback, referrer_policy) {
-  var iframe = appendIframeToBody(url, referrer_policy);
-  var listener = function(event) {
+function queryIframe(url, callback, attributes, referrer_policy, test) {
+  var iframe = appendIframeToBody(url, attributes);
+  var listener = test.step_func(function(event) {
     if (event.source != iframe.contentWindow)
       return;
 
     callback(event.data, url);
     window.removeEventListener("message", listener);
-  }
+  });
   window.addEventListener("message", listener);
 }
 
@@ -122,12 +122,12 @@ function queryImage(url, callback, attributes, referrerPolicy, test) {
   var noSrcDocPolicy = new Promise((resolve, reject) => {
     var iframeWithoutOwnPolicy = document.createElement('iframe');
     iframeWithoutOwnPolicy.srcdoc = "Hello, world.";
-    iframeWithoutOwnPolicy.onload = function () {
+    iframeWithoutOwnPolicy.onload = test.step_func(function () {
       var nextUrl = url + "&cache_destroyer2=" + (new Date()).getTime();
-      loadImageInWindow(nextUrl, function (img) {
+      loadImageInWindow(nextUrl, test.step_func(function (img) {
         resolve(decodeImageData(extractImageData(img)));
-      }, attributes, iframeWithoutOwnPolicy.contentWindow);
-    };
+      }), attributes, iframeWithoutOwnPolicy.contentWindow);
+    });
     document.body.appendChild(iframeWithoutOwnPolicy);
   });
 
@@ -137,19 +137,19 @@ function queryImage(url, callback, attributes, referrerPolicy, test) {
     var iframeWithOwnPolicy = document.createElement('iframe');
     iframeWithOwnPolicy.srcdoc = "<meta name='referrer' content='" + iframePolicy + "'>Hello world.";
 
-    iframeWithOwnPolicy.onload = function () {
+    iframeWithOwnPolicy.onload = test.step_func(function () {
       var nextUrl = url + "&cache_destroyer3=" + (new Date()).getTime();
-      loadImageInWindow(nextUrl, function (img) {
+      loadImageInWindow(nextUrl, test.step_func(function (img) {
         resolve(decodeImageData(extractImageData(img)));
-      }, null, iframeWithOwnPolicy.contentWindow);
-    };
+      }), null, iframeWithOwnPolicy.contentWindow);
+    });
     document.body.appendChild(iframeWithOwnPolicy);
   });
 
   var pagePolicy = new Promise((resolve, reject) => {
-    loadImageInWindow(url, function (img) {
+    loadImageInWindow(url, test.step_func(function (img) {
       resolve(decodeImageData(extractImageData(img)));
-    }, attributes, window);
+    }), attributes, window);
   });
 
   Promise.all([noSrcDocPolicy, srcDocPolicy, pagePolicy]).then(test.step_func(values => {
@@ -159,52 +159,52 @@ function queryImage(url, callback, attributes, referrerPolicy, test) {
   }));
 }
 
-function queryXhr(url, callback) {
+function queryXhr(url, callback, attributes, referrer_policy, test) {
   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);
+  xhr.onreadystatechange = test.step_func(function(e) {
+    if (xhr.readyState == 4 && xhr.status == 200) {
+      var server_data = JSON.parse(xhr.responseText);
       callback(wrapResult(url, server_data), url);
     }
-  };
+  });
   xhr.send();
 }
 
-function queryWorker(url, callback) {
+function queryWorker(url, callback, attributes, referrer_policy, test) {
   var worker = new Worker(url);
-  worker.onmessage = function(event) {
+  worker.onmessage = test.step_func(function(event) {
     var server_data = event.data;
     callback(wrapResult(url, server_data), url);
-  };
+  });
 }
 
-function queryModuleWorkerTopLevel(url, callback) {
+function queryModuleWorkerTopLevel(url, callback, attributes, referrer_policy, test) {
   var worker = new Worker(url, {type: "module"});
-  worker.onmessage = function(event) {
+  worker.onmessage = test.step_func(function(event) {
     var server_data = event.data;
     callback(wrapResult(url, server_data), url);
-  };
+  });
 }
 
-function querySharedWorker(url, callback) {
+function querySharedWorker(url, callback, attributes, referrer_policy, test) {
   var worker = new SharedWorker(url);
-  worker.port.onmessage = function(event) {
+  worker.port.onmessage = test.step_func(function(event) {
     var server_data = event.data;
     callback(wrapResult(url, server_data), url);
-  };
+  });
 }
 
-function queryFetch(url, callback) {
-  fetch(url).then(function(response) {
-      response.json().then(function(server_data) {
+function queryFetch(url, callback, attributes, referrer_policy, test) {
+  fetch(url).then(test.step_func(function(response) {
+      response.json().then(test.step_func(function(server_data) {
         callback(wrapResult(url, server_data), url);
-      });
-    }
+      }));
+    })
   );
 }
 
-function queryNavigable(element, url, callback, attributes) {
+function queryNavigable(element, url, callback, attributes, test) {
   var navigable = element
   navigable.href = url;
   navigable.target = "helper-iframe";
@@ -220,42 +220,41 @@ function queryNavigable(element, url, callback, attributes) {
     }
   }
 
-  var listener = function(event) {
+  var listener = test.step_func(function(event) {
     if (event.source != helperIframe.contentWindow)
       return;
-
     callback(event.data, url);
     window.removeEventListener("message", listener);
-  }
+  });
   window.addEventListener("message", listener);
 
   navigable.click();
 }
 
-function queryLink(url, callback, referrer_policy) {
+function queryLink(url, callback, attributes, referrer_policy, test) {
   var a = document.createElement("a");
   a.innerHTML = "Link to subresource";
   document.body.appendChild(a);
-  queryNavigable(a, url, callback, referrer_policy)
+  queryNavigable(a, url, callback, attributes, test)
 }
 
-function queryAreaLink(url, callback, referrer_policy) {
+function queryAreaLink(url, callback, attributes, referrer_policy, test) {
   var area = document.createElement("area");
   // TODO(kristijanburnik): Append to map and add image.
   document.body.appendChild(area);
-  queryNavigable(area, url, callback, referrer_policy)
+  queryNavigable(area, url, callback, attributes, test)
 }
 
-function queryScript(url, callback, attributes, referrer_policy) {
+function queryScript(url, callback, attributes, referrer_policy, test) {
   var script = document.createElement("script");
   script.src = url;
   script.referrerPolicy = referrer_policy;
 
-  var listener = function(event) {
+  var listener = test.step_func(function(event) {
     var server_data = event.data;
     callback(wrapResult(url, server_data), url);
     window.removeEventListener("message", listener);
-  }
+  });
   window.addEventListener("message", listener);
 
   document.body.appendChild(script);
diff --git a/tests/wpt/web-platform-tests/referrer-policy/generic/referrer-policy-test-case.js b/tests/wpt/web-platform-tests/referrer-policy/generic/referrer-policy-test-case.js
index 4641683cd85..2385cc2a1c4 100644
--- a/tests/wpt/web-platform-tests/referrer-policy/generic/referrer-policy-test-case.js
+++ b/tests/wpt/web-platform-tests/referrer-policy/generic/referrer-policy-test-case.js
@@ -96,31 +96,31 @@ function ReferrerPolicyTestCase(scenario, testDescription, sanityChecker) {
     },
 
     start: function() {
-      t._constructSubresourceUrl();
-      t._constructExpectedReferrerUrl();
+      async_test(function(test) {
 
-      var test = async_test(t._testDescription);
+        t._constructSubresourceUrl();
+        t._constructExpectedReferrerUrl();
 
-      t._invokeSubresource(function(result) {
-        // Check if the result is in valid format. NOOP in release.
-        sanityChecker.checkSubresourceResult(
-            test, t._scenario, t._subresourceUrl, result);
+        t._invokeSubresource(test.step_func(function(result) {
+          // Check if the result is in valid format. NOOP in release.
+          sanityChecker.checkSubresourceResult(
+              test, t._scenario, t._subresourceUrl, result);
 
-        // Check the reported URL.
-        test.step(function() {
-          assert_equals(result.referrer,
-                        t._expectedReferrerUrl,
-                        "Reported Referrer URL is '" +
-                        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);
+          // Check the reported URL.
+          test.step(function() {
+            assert_equals(result.referrer,
+                          t._expectedReferrerUrl,
+                          "Reported Referrer URL is '" +
+                          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);
+      }, t._testDescription);
     }
   }
 
diff --git a/tests/wpt/web-platform-tests/referrer-policy/generic/sandboxed-iframe-with-opaque-origin.html b/tests/wpt/web-platform-tests/referrer-policy/generic/sandboxed-iframe-with-opaque-origin.html
index 8fee77f8363..1b2b12bf691 100644
--- a/tests/wpt/web-platform-tests/referrer-policy/generic/sandboxed-iframe-with-opaque-origin.html
+++ b/tests/wpt/web-platform-tests/referrer-policy/generic/sandboxed-iframe-with-opaque-origin.html
@@ -13,26 +13,28 @@
     <h1>Referrer Policy: A document with an opaque origin doesn't send referrers</h1>
     <script>
       function testSandboxedIframe(description, sandboxAttributes, expectedReferrer) {
-        var test = async_test(description);
-        window.addEventListener("message", test.step_func((msg) => {
-          if (msg.data.description === description) {
-            assert_equals(msg.data.referrer, expectedReferrer);
-            test.done();
-          }
-        }));
+        async_test(function(test) {
+          window.addEventListener("message", test.step_func((msg) => {
+            if (msg.data.description === description) {
+              assert_equals(msg.data.referrer, expectedReferrer);
+              test.done();
+            }
+          }));
 
-        var iframe = document.createElement("iframe");
-        iframe.sandbox = sandboxAttributes;
-        iframe.srcdoc = `
-            <meta name = "referrer" content = "always">
-            <script src = "/referrer-policy/generic/common.js"></` + `script>
-            <script>
-              var urlPath = "/referrer-policy/generic/subresource/xhr.py";
-              var url = "${location.protocol}//www1.${location.hostname}:${location.port}" + urlPath;
-              queryXhr(url, (msg) => {
-                  parent.postMessage({referrer: msg.referrer, description: "${description}"}, "*")});
-            </` + "script>";
-        document.body.appendChild(iframe);
+          var iframe = document.createElement("iframe");
+          iframe.sandbox = sandboxAttributes;
+          iframe.srcdoc = `
+              <meta name = "referrer" content = "always">
+              <script src = "/referrer-policy/generic/common.js"></` + `script>
+              <script>
+                var urlPath = "/referrer-policy/generic/subresource/xhr.py";
+                var url = "${location.protocol}//www1.${location.hostname}:${location.port}" + urlPath;
+                queryXhr(url, (msg) => {
+                    parent.postMessage({referrer: msg.referrer, description: "${description}"}, "*")
+                }, null, null, test);
+              </` + "script>";
+          document.body.appendChild(iframe);
+        }, description);
       }
 
       testSandboxedIframe("Sandboxed iframe with opaque origin doesn't send referrers.", "allow-scripts", undefined);
diff --git a/tests/wpt/web-platform-tests/referrer-policy/generic/subresource-test/area-navigate.html b/tests/wpt/web-platform-tests/referrer-policy/generic/subresource-test/area-navigate.html
index bca7e479fa2..3eb824521b7 100644
--- a/tests/wpt/web-platform-tests/referrer-policy/generic/subresource-test/area-navigate.html
+++ b/tests/wpt/web-platform-tests/referrer-policy/generic/subresource-test/area-navigate.html
@@ -16,22 +16,21 @@
     <pre id="received_message">Running...</pre>
 
     <script>
-      var messaging_test = async_test("Area is responding with HTTP headers");
-      var urlPath = '/referrer-policy/generic/subresource/document.py';
-      var url = location.protocol + "//www1." + location.hostname + ":" + location.port +
-                urlPath;
-      queryAreaLink(url, function(message) {
-        var pre = document.getElementById('received_message')
-        var headers = message.headers;
-        pre.innerHTML = "";
-        pre.innerHTML += url + ":\n\n";
-        pre.innerHTML += JSON.stringify(headers, null, 2) + "\n\n"
-        messaging_test.step(function() {
+      async_test(function(messaging_test) {
+        var urlPath = '/referrer-policy/generic/subresource/document.py';
+        var url = location.protocol + "//www1." + location.hostname + ":" + location.port +
+                  urlPath;
+        queryAreaLink(url, function(message) {
+          var pre = document.getElementById('received_message')
+          var headers = message.headers;
+          pre.innerHTML = "";
+          pre.innerHTML += url + ":\n\n";
+          pre.innerHTML += JSON.stringify(headers, null, 2) + "\n\n"
           assert_own_property(headers, "host")
           assert_own_property(headers, "connection")
-        });
-        messaging_test.done();
-      });
+          messaging_test.done();
+        }, null, null, messaging_test);
+      }, "Area is responding with HTTP headers");
     </script>
 
     <div id="log"></div>
diff --git a/tests/wpt/web-platform-tests/referrer-policy/generic/subresource-test/fetch-messaging.html b/tests/wpt/web-platform-tests/referrer-policy/generic/subresource-test/fetch-messaging.html
index 046b29e9a3e..edb159d9eb1 100644
--- a/tests/wpt/web-platform-tests/referrer-policy/generic/subresource-test/fetch-messaging.html
+++ b/tests/wpt/web-platform-tests/referrer-policy/generic/subresource-test/fetch-messaging.html
@@ -24,22 +24,21 @@
         if (!window.fetch)
           return;
 
-        var fetch_test = async_test("Fetch is responding with HTTP headers");
-        var urlPath = '/referrer-policy/generic/subresource/xhr.py';
-        var url = location.protocol + "//" + location.hostname + ":" +
-                  location.port + urlPath;
-        queryFetch(url, function(message) {
-          var pre = document.getElementById('received_message')
-          var headers = message.headers;
-          pre.innerHTML = "";
-          pre.innerHTML += url + ":\n\n";
-          pre.innerHTML += JSON.stringify(headers, null, 2) + "\n\n";
-          fetch_test.step(function() {
+        async_test(function(fetch_test) {
+          var urlPath = '/referrer-policy/generic/subresource/xhr.py';
+          var url = location.protocol + "//" + location.hostname + ":" +
+                    location.port + urlPath;
+          queryFetch(url, function(message) {
+            var pre = document.getElementById('received_message')
+            var headers = message.headers;
+            pre.innerHTML = "";
+            pre.innerHTML += url + ":\n\n";
+            pre.innerHTML += JSON.stringify(headers, null, 2) + "\n\n";
             assert_own_property(headers, "host")
             assert_own_property(headers, "connection")
-          });
-          fetch_test.done();
-        });
+            fetch_test.done();
+          }, null, null, fetch_test);
+        }, "Fetch is responding with HTTP headers");
       })();
     </script>
 
diff --git a/tests/wpt/web-platform-tests/referrer-policy/generic/subresource-test/iframe-messaging.html b/tests/wpt/web-platform-tests/referrer-policy/generic/subresource-test/iframe-messaging.html
index a3e55707c26..606e18b281f 100644
--- a/tests/wpt/web-platform-tests/referrer-policy/generic/subresource-test/iframe-messaging.html
+++ b/tests/wpt/web-platform-tests/referrer-policy/generic/subresource-test/iframe-messaging.html
@@ -16,22 +16,21 @@
     <pre id="received_message">Running...</pre>
 
     <script>
-      var messaging_test = async_test("Iframe is responding with HTTP headers");
-      var urlPath = '/referrer-policy/generic/subresource/document.py';
-      var url = location.protocol + "//www1." + location.hostname + ":" + location.port +
-                urlPath;
-      queryIframe(url, function(message) {
-        var pre = document.getElementById('received_message')
-        var headers = message.headers;
-        pre.innerHTML = "";
-        pre.innerHTML += url + ":\n\n";
-        pre.innerHTML += JSON.stringify(headers, null, 2) + "\n\n"
-        messaging_test.step(function() {
+      async_test(function(messaging_test) {
+        var urlPath = '/referrer-policy/generic/subresource/document.py';
+        var url = location.protocol + "//www1." + location.hostname + ":" + location.port +
+                  urlPath;
+        queryIframe(url, function(message) {
+          var pre = document.getElementById('received_message')
+          var headers = message.headers;
+          pre.innerHTML = "";
+          pre.innerHTML += url + ":\n\n";
+          pre.innerHTML += JSON.stringify(headers, null, 2) + "\n\n"
           assert_own_property(headers, "host")
           assert_own_property(headers, "connection")
-        });
-        messaging_test.done();
-      });
+          messaging_test.done();
+        }, null, null, messaging_test);
+      }, "Iframe is responding with HTTP headers");
     </script>
 
     <div id="log"></div>
diff --git a/tests/wpt/web-platform-tests/referrer-policy/generic/subresource-test/image-decoding.html b/tests/wpt/web-platform-tests/referrer-policy/generic/subresource-test/image-decoding.html
index 448f12b1348..9c50ea66193 100644
--- a/tests/wpt/web-platform-tests/referrer-policy/generic/subresource-test/image-decoding.html
+++ b/tests/wpt/web-platform-tests/referrer-policy/generic/subresource-test/image-decoding.html
@@ -16,22 +16,21 @@
     <pre id="received_message">Running...</pre>
 
     <script>
-      var messaging_test = async_test("Image is encoding headers as JSON.");
-      var urlPath = '/referrer-policy/generic/subresource/image.py';
-      var url = location.protocol + "//www1." + location.hostname + ":" + location.port +
-                urlPath + "?cache_destroyer=" + (new Date()).getTime();
-      queryImage(url, function(message) {
-        var pre = document.getElementById('received_message')
-        var headers = message.headers;
-        pre.innerHTML = "";
-        pre.innerHTML += url + ":\n\n";
-        pre.innerHTML += JSON.stringify(headers, null, 2) + "\n\n"
-        messaging_test.step(function() {
+      async_test(function(messaging_test) {
+        var urlPath = '/referrer-policy/generic/subresource/image.py';
+        var url = location.protocol + "//www1." + location.hostname + ":" + location.port +
+                  urlPath + "?cache_destroyer=" + (new Date()).getTime();
+        queryImage(url, function(message) {
+          var pre = document.getElementById('received_message')
+          var headers = message.headers;
+          pre.innerHTML = "";
+          pre.innerHTML += url + ":\n\n";
+          pre.innerHTML += JSON.stringify(headers, null, 2) + "\n\n"
           assert_own_property(headers, "host")
           assert_own_property(headers, "connection")
-        });
-        messaging_test.done();
-      }, null, "always", messaging_test);
+          messaging_test.done();
+        }, null, "always", messaging_test);
+      }, "Image is encoding headers as JSON.");
     </script>
 
     <div id="log"></div>
diff --git a/tests/wpt/web-platform-tests/referrer-policy/generic/subresource-test/link-navigate.html b/tests/wpt/web-platform-tests/referrer-policy/generic/subresource-test/link-navigate.html
index 45e502004d4..95582f65bac 100644
--- a/tests/wpt/web-platform-tests/referrer-policy/generic/subresource-test/link-navigate.html
+++ b/tests/wpt/web-platform-tests/referrer-policy/generic/subresource-test/link-navigate.html
@@ -16,22 +16,21 @@
     <pre id="received_message">Running...</pre>
 
     <script>
-      var messaging_test = async_test("Link is responding with HTTP headers");
-      var urlPath = '/referrer-policy/generic/subresource/document.py';
-      var url = location.protocol + "//www1." + location.hostname + ":" + location.port +
-                urlPath;
-      queryLink(url, function(message) {
-        var pre = document.getElementById('received_message')
-        var headers = message.headers;
-        pre.innerHTML = "";
-        pre.innerHTML += url + ":\n\n";
-        pre.innerHTML += JSON.stringify(headers, null, 2) + "\n\n"
-        messaging_test.step(function() {
+      async_test(function(messaging_test) {
+        var urlPath = '/referrer-policy/generic/subresource/document.py';
+        var url = location.protocol + "//www1." + location.hostname + ":" + location.port +
+                  urlPath;
+        queryLink(url, function(message) {
+          var pre = document.getElementById('received_message')
+          var headers = message.headers;
+          pre.innerHTML = "";
+          pre.innerHTML += url + ":\n\n";
+          pre.innerHTML += JSON.stringify(headers, null, 2) + "\n\n"
           assert_own_property(headers, "host")
           assert_own_property(headers, "connection")
-        });
-        messaging_test.done();
-      });
+          messaging_test.done();
+        }, null, null, messaging_test);
+      }, "Link is responding with HTTP headers");
     </script>
 
     <div id="log"></div>
diff --git a/tests/wpt/web-platform-tests/referrer-policy/generic/subresource-test/script-messaging.html b/tests/wpt/web-platform-tests/referrer-policy/generic/subresource-test/script-messaging.html
index 09c5db6193f..f73f4406df2 100644
--- a/tests/wpt/web-platform-tests/referrer-policy/generic/subresource-test/script-messaging.html
+++ b/tests/wpt/web-platform-tests/referrer-policy/generic/subresource-test/script-messaging.html
@@ -16,22 +16,21 @@
     <pre id="received_message">Running...</pre>
 
     <script>
-      var messaging_test = async_test("Script is responding with HTTP headers");
-      var urlPath = '/referrer-policy/generic/subresource/script.py';
-      var url = location.protocol + "//www1." + location.hostname + ":" + location.port +
-                urlPath;
-      queryScript(url, function(message) {
-        var pre = document.getElementById('received_message')
-        var headers = message.headers;
-        pre.innerHTML = "";
-        pre.innerHTML += url + ":\n\n";
-        pre.innerHTML += JSON.stringify(headers, null, 2) + "\n\n"
-        messaging_test.step(function() {
+      async_test(function(messaging_test) {
+        var urlPath = '/referrer-policy/generic/subresource/script.py';
+        var url = location.protocol + "//www1." + location.hostname + ":" + location.port +
+                  urlPath;
+        queryScript(url, function(message) {
+          var pre = document.getElementById('received_message')
+          var headers = message.headers;
+          pre.innerHTML = "";
+          pre.innerHTML += url + ":\n\n";
+          pre.innerHTML += JSON.stringify(headers, null, 2) + "\n\n"
           assert_own_property(headers, "host")
           assert_own_property(headers, "connection")
-        });
-        messaging_test.done();
-      });
+          messaging_test.done();
+        }, null, null, messaging_test);
+      }, "Script is responding with HTTP headers");
     </script>
 
     <div id="log"></div>
diff --git a/tests/wpt/web-platform-tests/referrer-policy/generic/subresource-test/worker-messaging.html b/tests/wpt/web-platform-tests/referrer-policy/generic/subresource-test/worker-messaging.html
index 6d34366b943..fd7591882e9 100644
--- a/tests/wpt/web-platform-tests/referrer-policy/generic/subresource-test/worker-messaging.html
+++ b/tests/wpt/web-platform-tests/referrer-policy/generic/subresource-test/worker-messaging.html
@@ -16,22 +16,21 @@
     <pre id="received_message">Running...</pre>
 
     <script>
-      var messaging_test = async_test("Worker is responding with HTTP headers");
-      var urlPath = '/referrer-policy/generic/subresource/worker.py';
-      var url = location.protocol + "//" + location.hostname + ":" +
-                location.port + urlPath;
-      queryWorker(url, function(message) {
-        var pre = document.getElementById('received_message')
-        var headers = message.headers;
-        pre.innerHTML = "";
-        pre.innerHTML += url + ":\n\n";
-        pre.innerHTML += JSON.stringify(headers, null, 2) + "\n\n"
-        messaging_test.step(function() {
+      async_test(function(messaging_test) {
+        var urlPath = '/referrer-policy/generic/subresource/worker.py';
+        var url = location.protocol + "//" + location.hostname + ":" +
+                  location.port + urlPath;
+        queryWorker(url, function(message) {
+          var pre = document.getElementById('received_message')
+          var headers = message.headers;
+          pre.innerHTML = "";
+          pre.innerHTML += url + ":\n\n";
+          pre.innerHTML += JSON.stringify(headers, null, 2) + "\n\n"
           assert_own_property(headers, "host")
           assert_own_property(headers, "connection")
-        });
-        messaging_test.done();
-      });
+          messaging_test.done();
+        }, null, null, messaging_test);
+      }, "Worker is responding with HTTP headers");
     </script>
 
     <div id="log"></div>
diff --git a/tests/wpt/web-platform-tests/referrer-policy/generic/subresource-test/xhr-messaging.html b/tests/wpt/web-platform-tests/referrer-policy/generic/subresource-test/xhr-messaging.html
index 09f69140098..6ef4a9cfd4b 100644
--- a/tests/wpt/web-platform-tests/referrer-policy/generic/subresource-test/xhr-messaging.html
+++ b/tests/wpt/web-platform-tests/referrer-policy/generic/subresource-test/xhr-messaging.html
@@ -16,22 +16,21 @@
     <pre id="received_message">Running...</pre>
 
     <script>
-      var messaging_test = async_test("XHR is responding with HTTP headers");
-      var urlPath = '/referrer-policy/generic/subresource/xhr.py';
-      var url = location.protocol + "//www1." + location.hostname + ":" + location.port +
-                urlPath;
-      queryXhr(url, function(message) {
-        var pre = document.getElementById('received_message')
-        var headers = message.headers;
-        pre.innerHTML = "";
-        pre.innerHTML += url + ":\n\n";
-        pre.innerHTML += JSON.stringify(headers, null, 2) + "\n\n"
-        messaging_test.step(function() {
+      async_test(function(messaging_test) {
+        var urlPath = '/referrer-policy/generic/subresource/xhr.py';
+        var url = location.protocol + "//www1." + location.hostname + ":" + location.port +
+                  urlPath;
+        queryXhr(url, function(message) {
+          var pre = document.getElementById('received_message')
+          var headers = message.headers;
+          pre.innerHTML = "";
+          pre.innerHTML += url + ":\n\n";
+          pre.innerHTML += JSON.stringify(headers, null, 2) + "\n\n"
           assert_own_property(headers, "host")
           assert_own_property(headers, "connection")
-        });
-        messaging_test.done();
-      });
+          messaging_test.done();
+        }, null, null, messaging_test);
+      }, "XHR is responding with HTTP headers");
     </script>
 
     <div id="log"></div>
diff --git a/tests/wpt/web-platform-tests/referrer-policy/generic/unsupported-csp-referrer-directive.html b/tests/wpt/web-platform-tests/referrer-policy/generic/unsupported-csp-referrer-directive.html
index 9627d165599..475efa55091 100644
--- a/tests/wpt/web-platform-tests/referrer-policy/generic/unsupported-csp-referrer-directive.html
+++ b/tests/wpt/web-platform-tests/referrer-policy/generic/unsupported-csp-referrer-directive.html
@@ -15,14 +15,15 @@
     <pre id="received_message">Running...</pre>
 
     <script>
-      var test = async_test("Image has a referrer despite CSP 'referrer' directive");
-      var urlPath = '/referrer-policy/generic/subresource/image.py?cache_destroyer=' + (new Date()).getTime();
-      var url = location.protocol + "//www1." + location.hostname + ":" + location.port +
-                urlPath;
-      queryImage(url, test.step_func(function(message) {
-        assert_equals(message.referrer, document.location.href);
-        test.done();
-      }), null, 'always', test);
+      async_test(function(test) {
+        var urlPath = '/referrer-policy/generic/subresource/image.py?cache_destroyer=' + (new Date()).getTime();
+        var url = location.protocol + "//www1." + location.hostname + ":" + location.port +
+                  urlPath;
+        queryImage(url, function(message) {
+          assert_equals(message.referrer, document.location.href);
+          test.done();
+        }, null, 'always', test);
+      }, "Image has a referrer despite CSP 'referrer' directive");
     </script>
 
     <div id="log"></div>