This extension is core in 3.2

Bug: angleproject:3573
Change-Id: If08736759da2fdc680cfa396d354dbfa97d1a60f
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2317040
Commit-Queue: Jonah Ryan-Davis <jonahr@google.com>
Reviewed-by: Tim Van Patten <timvp@google.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>