So that this class can use propagated field trials instead of the global Bug: webrtc:42220378 Change-Id: Ic1dba0c4967735606904329f7e9e6c09f186b809 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/350641 Reviewed-by: Erik Språng <sprang@webrtc.org> Reviewed-by: Philip Eliasson <philipel@webrtc.org> Commit-Queue: Danil Chapovalov <danilchap@webrtc.org> Cr-Commit-Position: refs/heads/main@{#42326}