GitLab

Removes oauth2_token_fetcher_ and auth_url_loader_factory_ from
OAuth2LoginManager, as they are no longer used - the usage was removed
in CL:1212962

BUG=None

Change-Id: Ia025818376f239e406dd285cdd288dca164c0ed2
Reviewed-on: https://chromium-review.googlesource.com/c/1347447Reviewed-by: Jacob Dufault <jdufault@chromium.org>
Commit-Queue: Toni Baržić <tbarzic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#610253}