Support correct validation for samplerParameterf with GL_TEXTURE_MAX_ANISOTROPY_EXT Bug: angleproject:2072 Change-Id: I3e0b63f2a63e8769e3eab2be3aa0403317ed0707 Reviewed-on: https://chromium-review.googlesource.com/881707 Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Luc Ferron <lucferron@google.com>