GitLab

This patch adds the ability to resolve ESNI (TLS 1.3 Encrypted
Server Name Indication, draft 4) results concurrently with A and
AAAA records during connection establishment.

This is behind a base::Feature, disabled by default. When the
feature is enabled and DNS over HTTPS is in use, the built-in
resolver will make an additional ESNI transaction concurrently with
the usual ones of type A and AAAA. It also starts a timer (initially
set to the 50ms recommended by the spec) past which to abandon
the ESNI transaction without failing the DNS task.

R=ericorth

Bug: 1003494
Change-Id: Ia73b5e910f2a466b6384c7c73f09705e770ea39d
Cq-Do-Not-Cancel-Tryjobs: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1879430
Commit-Queue: David Van Cleve <davidvc@chromium.org>
Reviewed-by: Eric Orth <ericorth@chromium.org>
Cr-Commit-Position: refs/heads/master@{#712131}