For readability. Also make them constexpr, which allows to use them in
other constexpr contexts.

R=mstarzinger@chromium.org

Change-Id: Ia9ea9b4fb044bd1a011da887409bfbcbf6298fec
Reviewed-on: https://chromium-review.googlesource.com/647627Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47785}