Remove Common Name Fallback code

Use of the common name for matching the hostname is fundamentally
insecure, as it allows for the bypass of security controls within
certificates. Remove the remaining aspects of supporting logic that
allow common name fallback, which were enabled by Enterprise Policy,
now that the Enterprise Policy has been removed.

BUG: 804349

Cq-Include-Trybots: master.tryserver.chromium.android:android_cronet_tester;master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: I6e595f106b0d989935c9edc0d4c02e9a0f0f4584
Reviewed-on: https://chromium-review.googlesource.com/878901
Commit-Queue: Ryan Sleevi <rsleevi@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Misha Efimov <mef@chromium.org>
Reviewed-by: Eric Roman <eroman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#531345}
30 files changed