This optimization allows iterating only over updates of a certain level
or range of levels, instead of having to iterate over every update and
filter out the ones matching the desired level(s).

Bug: angleproject:4891
Change-Id: Ied04f4b28f05d37b9add61c7f4d54cc328c0be86
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2519095Reviewed-by: Tim Van Patten <timvp@google.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>