Let the OutgoingStream reference the parent instead of passing
references to individual items it needs, as follow-up CLs will add even
more items.
No functional change - pure refactoring.
Bug: webrtc:5696
Change-Id: I914e590c0d90e898d7d230a16170cf4faff2338c
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/264142
Reviewed-by: Florent Castelli <orphis@webrtc.org>
Commit-Queue: Victor Boivie <boivie@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#37398}