[s13n] Convert CWVSyncController to IdentityManager

This CL only migrates CWVSyncController production code away from
SigninManager, leaves migration away from ProfileOAuth2TokenService
and AccountTrackerService for a follow up step.

Bug: 903838
Change-Id: Ifc8e1f471554af3211bd020112265d57c9360e72
Reviewed-on: https://chromium-review.googlesource.com/c/1404543
Reviewed-by: Hiroshi Ichikawa <ichikawa@chromium.org>
Reviewed-by: Sylvain Defresne <sdefresne@chromium.org>
Commit-Queue: Julie Jeongeun Kim <jkim@igalia.com>
Cr-Commit-Position: refs/heads/master@{#623126}
4 files changed