That accessor forces test helpers to create BasicPortAllocator themself rather than deligate such task to PeerConnectionFactory Bug: webrtc:42232556 Change-Id: I262e032da110222198e6308f57a5e5f2d7ba4601 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/376741 Reviewed-by: Artem Titov <titovartem@webrtc.org> Reviewed-by: Harald Alvestrand <hta@webrtc.org> Commit-Queue: Danil Chapovalov <danilchap@webrtc.org> Cr-Commit-Position: refs/heads/main@{#43870}