Also enable the dEQP test that was blocked on that UNIMPLEMENTED call.

Bug: angleproject:2600
Change-Id: Iae1280d6e4f52c5b8e66c9f7fbaa9b2730c4eb0e
Reviewed-on: https://chromium-review.googlesource.com/1085693Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Luc Ferron <lucferron@chromium.org>