Most of the checks are unnecessary
Created attachment 270269 [details]
It looks like this patch may have caused 4 tests to fail:
Reverted r195871 for reason:
Caused several layout tests to time out
Committed r195909: <http://trac.webkit.org/changeset/195909>
Relanded in http://trac.webkit.org/changeset/196023 with 1 minute timer to avoid suspending tests that explicitly set page to non-visible state.