This changes most deletion paths of Connection objects to go through
the owner class of the Connection instances, Port.
In situations where Connection objects still need to be deleted
asynchronously, `async = true` can be passed to
`Port::DestroyConnection` and get the same behavior as
`Connection::Destroy` formerly gave.
The `Destroy()` method still exists for downstream compatibility, but
instead of deleting connection objects asynchronously, the deletion
now happens synchronously via the Port class.
Bug: webrtc:13892, webrtc:13865
Change-Id: I07edb7bb5e5d93b33542581b4b09def548de9e12
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/259826
Reviewed-by: Danil Chapovalov <danilchap@webrtc.org>
Commit-Queue: Tomas Gunnarsson <tommi@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#36676}
942cac2e9e