1 files changed, 24 insertions, 0 deletions
diff --git a/testing/web-platform/tests/html/semantics/embedded-content/the-iframe-element/support/load-into-the-iframe.html b/testing/web-platform/tests/html/semantics/embedded-content/the-iframe-element/support/load-into-the-iframe.html
new file mode 100644
index 0000000000..9e08eb587a
--- /dev/null
+++ b/testing/web-platform/tests/html/semantics/embedded-content/the-iframe-element/support/load-into-the-iframe.html
@@ -0,0 +1,24 @@
+
+<!DOCTYPE html>
+<html>
+  <head>
+    <meta charset="utf-8">
+  </head>
+  <body>
+    <iframe sandbox="allow-scripts"></iframe>
+    <script>
+      let frame = document.querySelector("iframe");
+      let sandbox = new URL(location.href).searchParams.get("sandbox");
+      if (sandbox) {
+        frame.sandbox = sandbox;
+      }
+      // We're the popup (i.e. a top frame).  Load into the iframe the page
+      // trying to modifying the top frame and transmit the result to our
+      // opener.
+      onmessage = function(e) {
+        opener.postMessage(e.data, "*")
+      }
+      frame.src = "iframe-that-performs-top-navigation-on-popup.html";
+    </script>
+  </body>
+</html>