GitLab

This patch removes mutex from AllStatus class and introduces
SyncStatusObserver instead of getting of status directly from AllStatus
from different threads. AllStatus becomes single-threaded now.

Status for debugging is stored in SyncEngineImpl.

Bug: 1058773
Change-Id: Ib1d30d5ff6bc5bc5e1f24e94499de949f1e2e053
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2089695
Commit-Queue: Rushan Suleymanov <rushans@google.com>
Reviewed-by: Marc Treib <treib@chromium.org>
Reviewed-by: vitaliii <vitaliii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#748611}