[Managed Session] Activate managed session mode when risky extension is installed

Managed session mode now is only activated when any "risky" extensions are force-installed.
Right now an extension is considered "risky" if it's force-installed, but not whitelisted.

Bug: 910218
Change-Id: I42cc76e3723513b23f827c99505a096e3832a94d
Reviewed-on: https://chromium-review.googlesource.com/c/1391589
Commit-Queue: Zakhar Voit <voit@google.com>
Reviewed-by: Jacob Dufault <jdufault@chromium.org>
Reviewed-by: Sergey Poromov <poromov@chromium.org>
Cr-Commit-Position: refs/heads/master@{#625159}
2 files changed