A DCHECK in TimeTicks::HighResolutionNow was replaced with
a warning to stop systems from crashing. This warning broke
parts of the Node.js test-suite on certain systems.

The warning has been replaced with a comment documenting
this situation and a TODO to ensure we don't lose track
of this code path.

Bug: v8:7617
Bug: chromium:809016
Change-Id: I5e3af8c31817291d264af861514f34e3e1af9af2
Reviewed-on: https://chromium-review.googlesource.com/997153Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Commit-Queue: Myles Borins <mborins@google.com>
Cr-Commit-Position: refs/heads/master@{#52458}