GitLab

Settings entry to switch sync accounts has been removed,
so this CL removes dialogs that are no longer used.

Bug: 1007331
Change-Id: I368b2115404696b41d355997ae297f921347b7af
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1821612
Commit-Queue: Boris Sazonov <bsazonov@chromium.org>
Reviewed-by: Alex Ilin <alexilin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#700401}