commit 52320eed95faa917c381c0a4532252d9314171fa
author Tommi <tommi@webrtc.org> Sun Sep 14 07:46:12 2025
committer WebRTC LUCI CQ <webrtc-scoped@luci-project-accounts.iam.gserviceaccount.com> Sun Sep 14 08:42:13 2025
tree ab3cbdcb821346d6522961218b71e5d3d4d6e850
parent 86a538129db71b3ec61179d5d05c56786af8937d

Change who gets the clone when creating SDPs in SdpOfferAnswerHandler

Previously, `CreateDescriptionObserverWrapperWithCreationCallback` and
associated callbacks, created a clone of the new sdp for internal
storage (last_created_offer_ and last_created_answer_) passed the
original session description to the wrapped observer.

This patch inverts the logic and gives the cloned object to the wrapped
observer instead. The reason for that is that in order to create a
clone, the state of the original object needs to be accessed and doing
so will (once thread checkers are in place) pin that state to the
calling thread. The calling thread is the signaling thread, which is
suitable for SdpOfferAnswerHandler but the wrapped observer should get
the pristine object which is less bound.

A side effect of this CL may be that we'll get less flake on tsan bots
since a test observer implementation will now get a newly constructed
object rather than one who's state may be accessed on different threads
in parallel. However, the local_description() and remote_description()
accessors still need to be fixed (wip).

Along the way use AnyInvocable&& instead of std::function.

Bug: webrtc:442220720
Change-Id: Idfef673b59e1f50bc2a6e82fb142d5f1aa528d8b
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/409280
Commit-Queue: Tomas Gunnarsson <tommi@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#45646}