Nothing in regression tests is ever guaranteed to happen within 50 milliseconds. Especially with hyper-threading, a process can run very very slowly.
Created attachment 243501 [details] proposed fix
*** Bug 85523 has been marked as a duplicate of this bug. ***
*** Bug 90708 has been marked as a duplicate of this bug. ***
Comment on attachment 243501 [details] proposed fix Clearing flags on attachment: 243501 Committed r177507: <http://trac.webkit.org/changeset/177507>
All reviewed patches have been landed. Closing bug.