GitLab

Two cases are updated for signin intercept to Guest mode:
 1- When Guest mode is disabled by policy, this will not be offered.
 2- If user opens a Guest profile whie signin intercept is showing,
    and chooses to go to Guest mode, this will be done.

Bug: 1157764
Change-Id: I4116b2c32125a76d893911eebe1c2c31b2284231
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2620559Reviewed-by: David Roger <droger@chromium.org>
Commit-Queue: Ramin Halavati <rhalavati@chromium.org>
Cr-Commit-Position: refs/heads/master@{#841956}