GitLab

This is a reland of ded13f7d

Original change's description:
> Followup cleanup for ProfileSyncServiceUsesTaskScheduler experiment code.
>
> 1) Remove sync_thread_ from the ProfileSyncService interface to avoid
> accidental use.
> 2) Enable experiment in tests to provide coverage.
> 3) Add some ScopedAllowBaseSyncPrimitives in code that needed it.
>
> Bug: 1014464
> Change-Id: I79393edac048a2960b4f2bc7593be326f5d27419
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1895797
> Commit-Queue: Oliver Li <olivierli@chromium.org>
> Reviewed-by: François Doray <fdoray@chromium.org>
> Reviewed-by: Mikel Astiz <mastiz@chromium.org>
> Auto-Submit: Oliver Li <olivierli@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#713459}

Bug: 1014464
Change-Id: I8d9a6d0fcf055f466d7e4a3b30a3c1e4e92042bf

TBR=fdoray@chromium.org, mastiz@chromium.org

Change-Id: I8d9a6d0fcf055f466d7e4a3b30a3c1e4e92042bf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1904309
Auto-Submit: Oliver Li <olivierli@chromium.org>
Commit-Queue: François Doray <fdoray@chromium.org>
Reviewed-by: François Doray <fdoray@chromium.org>
Cr-Commit-Position: refs/heads/master@{#713533}