Add an error page for resources blocked via XSS Auditor.

third_party/WebKit/LayoutTests/http/tests/security/frameNavigation/xss-DENIED-top-navigation-user-gesture-in-parent.html

Index: third_party/WebKit/LayoutTests/http/tests/security/frameNavigation/xss-DENIED-top-navigation-user-gesture-in-parent.html
diff --git a/third_party/WebKit/LayoutTests/http/tests/security/frameNavigation/xss-DENIED-top-navigation-user-gesture-in-parent.html b/third_party/WebKit/LayoutTests/http/tests/security/frameNavigation/xss-DENIED-top-navigation-user-gesture-in-parent.html
index c661318f3f28d53bb46cb3040828871de6d98e09..98aba2f0aefebc88006c550fdde0274d73886761 100644
--- a/third_party/WebKit/LayoutTests/http/tests/security/frameNavigation/xss-DENIED-top-navigation-user-gesture-in-parent.html
+++ b/third_party/WebKit/LayoutTests/http/tests/security/frameNavigation/xss-DENIED-top-navigation-user-gesture-in-parent.html
@@ -5,6 +5,7 @@ if (window.testRunner) {
     testRunner.dumpAsText();
     testRunner.dumpChildFramesAsText();
     testRunner.setDumpConsoleMessages(false);
+    testRunner.waitUntilDone();
 }
 
 // Ensure a user gesture happened in the main frame, but not in the iframe.
@@ -13,6 +14,13 @@ if (window.eventSender) {
     eventSender.mouseDown(0, 0);
     eventSender.mouseUp(0, 0);
 }
+
+window.addEventListener("message", e => {
+  if (e.data == "PASS")
+    setTimeout(_ => { testRunner.notifyDone(); }, 500); // Give the schedule blocking navigation time to fire.
+  else
+    testRunner.testFailed("'top.location' didn't throw.");
+});
 </script>
 <iframe src="http://localhost:8000/security/frameNavigation/resources/iframe-that-performs-top-navigation-without-user-gesture.html"></iframe>
 </body>