The sampler state may have changed even if the texture is already bound.

BUG=angleproject:884

Change-Id: I591f493099397bb07608096cf30ff46ed5090224
Reviewed-on: https://chromium-review.googlesource.com/263147Reviewed-by: Jamie Madill <jmadill@chromium.org>
Tested-by: Geoff Lang <geofflang@chromium.org>