Rewrite fast/workers/dedicated-worker-lifecycle.html to verify that
the GC is able to reclaim orphaned Workers on a timely basis.
https://bugs.webkit.org/show_bug.cgi?id=114893.

Reviewed by Geoffrey Garen.

* fast/workers/resources/dedicated-worker-lifecycle.js:
(orphanAllWorkers):
(runTests.worker.onmessage):
(runTests):
(orphanedWorkerExited.worker.onmessage):
(orphanedWorkerExited):
* fast/workers/resources/worker-util.js:
(waitUntilThreadCountMatchesCondition):
(waitUntilThreadCountMatches):
(waitUntilThreadCountDoesNotExceed):



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@148846 268f45cc-cd09-0410-ab3c-d52691b4dbfc