Update BrowserCommandController and tests for ephemeral Guest profiles.

A few commands are updated in browser command controller for ephemeral
Guest profiles and the tests are updated to cover both old (OTR) Guest
profiles and the new ephemeral ones.

Please see go/ephemeral-guest-profiles for more context.

Bug: 1125474
Change-Id: Ifa4890dab8d971aada471fca0a03861ca14c5e90
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2517588


Reviewed-by: Peter Kasting <pkasting@chromium.org>
Commit-Queue: Ramin Halavati <rhalavati@chromium.org>
Cr-Commit-Position: refs/heads/master@{#824318}