More consistent with the rest of the public functions in this class.

Bug: angleproject:4891
Change-Id: I72c7c3d21f8287cc1711772671c6e7ad524fd096
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2518179Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Tim Van Patten <timvp@google.com>
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>