Looks like r160896 fixed this test on some bots, but didn't on others. http://webkit-test-results.appspot.com/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=fast%2Fdynamic%2Fpaused-event-dispatch.html
Let's try increasing the timeout time. There might be some race conditions in the test here.
Committed r161008: <http://trac.webkit.org/changeset/161008>
Looks like the test has been passing now.