Don't use the mip level to validate the 2D texture depth parameter. BUG=angleproject:1149 Change-Id: I5dd45c99b373d480814c9fbdbe0abd419a270c89 Reviewed-on: https://chromium-review.googlesource.com/297052 Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Corentin Wallez <cwallez@chromium.org> Tested-by: Geoff Lang <geofflang@chromium.org>