This makes it possible for automated tests to distinguish between CHECK
failures and DCHECK failures, the latter of which will continue to run
in release builds after the assertion failure point.

Change-Id: Ie26978c0342d401a8c85f3261749739195087579
Reviewed-on: https://chromium-review.googlesource.com/565515
Commit-Queue: Daniel Clifford <danno@chromium.org>
Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46596}