Deletes the helper methods SdpSetObserver and SdpCreateObserver,
replaced with observer classes where used, in peer_scenario_client.cc.
Deletes the class webrtc_sdp_obs_impl::SdpSetObserversInterface, which
indirectly inherits rtc::RefCountInterface twice. Migrates this code
to use rtc::make_ref_counted, and migrates away from deprecated
versions of SetLocalDescription and SetRemoteDescription that use raw
pointers and SetSessionDescriptionObserver.
Bug: webrtc:12701, webrtc:11798
Change-Id: I18ea3fb51f533d7454a6dc75292b1827b1c80ef0
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/229981
Commit-Queue: Niels Moller <nisse@webrtc.org>
Reviewed-by: Tommi <tommi@webrtc.org>
Reviewed-by: Sebastian Jansson <srte@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#34843}
525dae03d6