We defautled to zero max bit depth, which breaks the swizzle format lookup.

Change-Id: I4d1cd8bcfb79db3460950fa22630c259f90fa432
Reviewed-on: https://chromium-review.googlesource.com/181481Reviewed-by: Jamie Madill <jmadill@google.com>
Commit-Queue: Jamie Madill <jmadill@google.com>
Reviewed-by: Shannon Woods <shannonwoods@chromium.org>
Tested-by: Jamie Madill <jmadill@chromium.org>