GitLab

Improve DNS configuration checking to handle additional cases where
we must defer to platform DNS, such as checking for DNS proxies and VPN
configurations, and an additional policy that could be used to
configure NRPT rules.

Bug: 1052139
Change-Id: I4884f76b576964e976114169113259e28fc78801
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2055761Reviewed-by: Eric Orth <ericorth@chromium.org>
Commit-Queue: Kaustubha Govind <kaustubhag@chromium.org>
Cr-Commit-Position: refs/heads/master@{#746643}