These accessors were introduced in https://codereview.webrtc.org/2789773004
for dynamic size extensions.
They are now implemented without need of these raw functions
Bug: None
Change-Id: Id43f0bcbf951d60ebeece49556b093956c5ad2bf
Reviewed-on: https://webrtc-review.googlesource.com/92626
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Reviewed-by: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24242}