Failing Chromium static initializers check:

FAILED linux-release-64/sizes/chrome-si/initializers: actual 8, expected 7, better lower

Possibly due to the static initializer for std::array for
the log severity types. We should change it to POD.

BUG=angleproject:1660

This reverts commit afcc41ce.

Change-Id: Ifb362a4af78542608397c7a0b19e6afe076f2cf3
Reviewed-on: https://chromium-review.googlesource.com/427235Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>