Fix ifdef complaints in clang

BUG=angle:677

Change-Id: Iee457dfc0990e5ffd61932b1f286f3c0208568bc
Reviewed-on: https://chromium-review.googlesource.com/203427
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Tested-by: Shannon Woods <shannonwoods@chromium.org>
8 files changed