Eliminate globalFlag usage from http security layout tests.

LayoutTests/http/tests/security/javascriptURL/xss-DENIED-to-javascript-url-in-foreign-domain-window-open.html

Index: LayoutTests/http/tests/security/javascriptURL/xss-DENIED-to-javascript-url-in-foreign-domain-window-open.html
diff --git a/LayoutTests/http/tests/security/javascriptURL/xss-DENIED-to-javascript-url-in-foreign-domain-window-open.html b/LayoutTests/http/tests/security/javascriptURL/xss-DENIED-to-javascript-url-in-foreign-domain-window-open.html
index 1526555b29bffedaf9174e2edd34d14a0a9ade90..1706266713897a4c9d8a2011ed553b9b68e80592 100644
--- a/LayoutTests/http/tests/security/javascriptURL/xss-DENIED-to-javascript-url-in-foreign-domain-window-open.html
+++ b/LayoutTests/http/tests/security/javascriptURL/xss-DENIED-to-javascript-url-in-foreign-domain-window-open.html
@@ -14,25 +14,11 @@
 
             openedWindow = window.open("http://localhost:8000/security/javascriptURL/resources/foreign-domain-javascript-url-accessee-opened-frame.html");
 
-            if (window.testRunner) {
-                setTimeout(pollForTest, 1);
-            } else {
-                log("To run the test, click the button below when the opened window finishes loading.");
-                var button = document.createElement("button");
-                button.appendChild(document.createTextNode("Run Test"));
-                button.onclick = runTest;
-                document.body.appendChild(button);
-            }
-        }
-
-        pollForTest = function()
-        {
-            if (!testRunner.globalFlag) {
-                setTimeout(pollForTest, 1);
-                return;
-            }
-            runTest();
-            closeWindowAndNotifyDone(openedWindow);
+            window.addEventListener('message', function ()
+            {
+                runTest();
+                closeWindowAndNotifyDone(openedWindow);
+            });
         }
 
         runTest = function()