Revert "Improve the thread flip."

This reverts commit e61e6fdd404b8f04bd33fc3ea49e38e92e31ad69.

ThreadStress failing.

Bug: 29517059
Bug: 12687968
Change-Id: I0ee8ef04f77c5f9378e4bd21c5dedb4e435a2dc6
6 files changed