[s13n] Move CWVSyncController away from AccountTrackerService

This CL removes AccountTrackerService from CWVSyncController
and uses IdentityManager instead of it.

Bug: 922801
Change-Id: Id9f588bbd534ccbaf79030423ddd0ceb98f95321
Reviewed-on: https://chromium-review.googlesource.com/c/1426200
Reviewed-by: Hiroshi Ichikawa <ichikawa@chromium.org>
Commit-Queue: Julie Jeongeun Kim <jkim@igalia.com>
Cr-Commit-Position: refs/heads/master@{#625033}
4 files changed