This fixes a warning.

BUG=angleproject:1668

Change-Id: Idf063be9dde0bfbf5f088d69ef38fd97baa69df3
Reviewed-on: https://chromium-review.googlesource.com/495434
Commit-Queue: Yuly Novikov <ynovikov@chromium.org>
Reviewed-by: Frank Henigman <fjhenigman@chromium.org>
Reviewed-by: Yuly Novikov <ynovikov@chromium.org>