1 files changed, 22 insertions, 14 deletions
diff --git a/testing/web-platform/tests/workers/same-site-cookies/third-party.all.tentative.sub.https.window.js b/testing/web-platform/tests/workers/same-site-cookies/third-party.all.tentative.sub.https.window.js
index 51ad1d3b02..21b53819d9 100644
--- a/testing/web-platform/tests/workers/same-site-cookies/third-party.all.tentative.sub.https.window.js
+++ b/testing/web-platform/tests/workers/same-site-cookies/third-party.all.tentative.sub.https.window.js
@@ -1,24 +1,32 @@
 // META: script=/resources/testdriver.js
 // META: script=/resources/testdriver-vendor.js
+// META: script=/workers/same-site-cookies/resources/util.js
 
 'use strict';
 
 // Here's the set-up for this test:
-// Step 1 (top-frame) Set up listener for "DidNotStart" message and open cross-site iframe.
-// Step 2 (sub-frame) Open iframe same-site to top-frame.
-// Step 3 (sub-sub-frame) Set up listener for message and start worker.
-// Step 4 (worker) Skipped.
-// Step 5 (sub-sub-frame) Worker failed to start and window messages "DidNotStart".
-// Step 6 (top-frame) Receive "DidNotStart" message and cleanup.
+// Step 1 (window) Set cookies.
+// Step 2 (top-frame) Set up listener for "DidNotStart" message and open cross-site iframe.
+// Step 3 (sub-frame) Open iframe same-site to top-frame.
+// Step 4 (sub-sub-frame) Set up listener for message and start worker.
+// Step 5 (redirect) Skipped.
+// Step 6 (worker) Skipped.
+// Step 7 (sub-sub-frame) Worker failed to start and window messages "DidNotStart".
+// Step 8 (top-frame) Receive "DidNotStart" message and cleanup.
 
 async_test(t => {
   // Step 1
-  window.addEventListener("message", t.step_func(e => {
-    // Step 6
-    assert_equals(e.data, "DidNotStart", "Worker should not have started");
-    t.done();
-  }));
-  let iframe = document.createElement("iframe");
-  iframe.src = "https://{{hosts[alt][]}}:{{ports[https][0]}}/workers/same-site-cookies/resources/iframe.sub.html?type=all";
-  document.body.appendChild(iframe);
+  const cookie_set_window = window.open("/workers/same-site-cookies/resources/set_cookies.py");
+  cookie_set_window.onload =  t.step_func(_ => {
+    // Step 2
+    window.addEventListener("message", t.step_func(e => {
+      // Step 8
+      assert_equals(e.data, "DidNotStart", "Worker should not have started");
+      cookie_set_window.close();
+      t.done();
+    }));
+    let iframe = document.createElement("iframe");
+    iframe.src = "https://{{hosts[alt][]}}:{{ports[https][0]}}/workers/same-site-cookies/resources/iframe.sub.html?type=all";
+    document.body.appendChild(iframe);
+  });
 }, "Check SharedWorker sameSiteCookies option all for third-party");