GitLab

Adding the annotation makes it clear which fields are protected by
base::Lock, and enables compile-time analysis to verify this.

BUG=893739,887645
TEST=compiles

Change-Id: Ibf8ff9b73f218fcd3cfeb4387e7ad406418ef522
Reviewed-on: https://chromium-review.googlesource.com/c/1303405Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Commit-Queue: John Rummell <jrummell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#604802}