http/tests/security/window-events-clear-port.html sometimes times out on Windows. See the URL for one such case.
I've added this test to the Skipped file.
<rdar://problem/8615538>
http/tests/security/window-properties-clear-port.html is also timing out fairly frequently on the Debug bots, e.g., <http://build.webkit.org/results/Windows%20Debug%20(Tests)/r71199%20(21909)/results.html>.