Add caps for the aggregate shader limits from table 6.33. BUG=angle:658 Change-Id: I59d0cd131114fcb925f01d83d218a657f4498a2a Reviewed-on: https://chromium-review.googlesource.com/207375 Reviewed-by: Jamie Madill <jmadill@chromium.org> Tested-by: Geoff Lang <geofflang@chromium.org>