1 files changed, 28 insertions, 0 deletions
diff --git a/testing/web-platform/tests/portals/resources/focus-page-with-x-origin-iframe.sub.html b/testing/web-platform/tests/portals/resources/focus-page-with-x-origin-iframe.sub.html
new file mode 100644
index 0000000000..df7974e75b
--- /dev/null
+++ b/testing/web-platform/tests/portals/resources/focus-page-with-x-origin-iframe.sub.html
@@ -0,0 +1,28 @@
+<!DOCTYPE html>
+<body>
+  <script>
+    async function handleMessage(e) {
+      if (e.data == "focus" || e.data == "focus-update-active-element") {
+        let iframe = document.querySelector("iframe");
+        iframe.contentWindow.postMessage(e.data, "*");
+      }
+    }
+
+    if (window.portalHost)
+      window.portalHost.onmessage = handleMessage;
+
+    window.onportalactivate = e => {
+      var portal = e.adoptPredecessor();
+      document.body.appendChild(portal);
+      portal.onmessage = handleMessage;
+    }
+
+    window.onmessage = e => {
+      if (window.portalHost)
+        window.portalHost.postMessage(e.data);
+      else
+        document.querySelector("portal").postMessage(e.data);
+    }
+  </script>
+  <iframe src="http://{{hosts[alt][www]}}:{{ports[http][0]}}/portals/resources/focus-page-with-button.html"></iframe>
+</body>