Moving the implementation to a source file. Bug: webrtc:13217 Change-Id: I2929f4af96a9d01d3adfa49b36b021e4b229a025 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/233241 Reviewed-by: Florent Castelli <orphis@webrtc.org> Commit-Queue: Victor Boivie <boivie@webrtc.org> Cr-Commit-Position: refs/heads/main@{#35116}