GitLab

This replaces SyncService::QuerySyncStatusSummaryString (which didn't
really make a whole lot of sense in the first place) and
SyncService::GetEngineInitializationStateString (which is now simply
a subset of the new State).

Bug: 839834
Change-Id: I9e3d9785a9bbafe5b8a7397b4a7c6c97acf9adf9
Reviewed-on: https://chromium-review.googlesource.com/1118223
Commit-Queue: Marc Treib <treib@chromium.org>
Reviewed-by: Mikel Astiz <mastiz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#572172}