GitLab

This reverts commit 62bb75d3.

Reason for revert: Decided we don't need this change

Original change's description:
> Oilpan: Rename to CrossThreadPersistentRegions
> 
> Rename CrossThreadPersistentRegion to CrossThreadPersistentRegions as we will be adding a second PersistentRegion for weak persistents:
> 
> BUG=757440
> 
> Change-Id: I751747470c5ddc1481270e181cdd1edcf9ae5291
> Reviewed-on: https://chromium-review.googlesource.com/882626
> Reviewed-by: Kentaro Hara <haraken@chromium.org>
> Commit-Queue: Keishi Hattori <keishi@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#531830}

TBR=haraken@chromium.org,keishi@chromium.org,hpayer@chromium.org,mlippautz@chromium.org

Change-Id: Ia1ac956e678dab92d6daab0852d0d9eafc3aa08a
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 757440
Reviewed-on: https://chromium-review.googlesource.com/886162Reviewed-by: Keishi Hattori <keishi@chromium.org>
Commit-Queue: Keishi Hattori <keishi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#531847}