Revert "[Profile Saver] Prevent a frequent lock/unlock of wait_lock_."

This reverts commit 2b637e24adefdf0c004fb3fae677f0f712339e02.

Reason for revert: It is still needed to keep the TimedWait when a stop signal is triggered to shutdown the thread

Change-Id: I117750b94919ba6689ca64fff835daa138bfb584