Revert "Bug 1047645 - Use manual timeout to guard _closed event from not firing r=alive"

This reverts commit bf33987e2729e82f1e3891eba3e85713f476fd0e.
Bug 1047645 - Use manual timeout to guard _closed event from not firing r=alive
Merge pull request #22940 from KevinGrandon/bug_1047645_system_timeout_reland_2

Bug 1047645 - Use manual timeout to guard _closed event from not firing