None of these functions needed to be member functions. Also make the
naming more consistent.

Bug: angleproject:3393
Change-Id: I7aafe2269a48af703a87bd9a8cf4cfab9e177dd3
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1574673Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>