Support arrays of arrays in UseInterfaceBlockFields This can be tested more fully once parsing arrays of arrays will be supported. BUG=angleproject:2125 Change-Id: I89c8f33b8cca5d6f5aa3f20aab23dccac53a956f Reviewed-on: https://chromium-review.googlesource.com/733128 Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>