GitLab

When there's only one web account to turn on sync,
the "Sync to another account" button should directly open
the sign-in flow for a new account instead of opening
a submenu with only the "Use another account" button.

Bug: 812269
Change-Id: I99757042f9a03b78c8145cb13faea893b64db32a
Reviewed-on: https://chromium-review.googlesource.com/924185
Commit-Queue: Thomas Tangl <tangltom@chromium.org>
Reviewed-by: Trent Apted <tapted@chromium.org>
Cr-Commit-Position: refs/heads/master@{#537622}