This allows to delete non-needed headers from .h files. Ran this on peer_connection.cc to demonstrate. Bug: none Change-Id: I69ce48be25a9778297e521282898c6ac31e7ea6c Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/254600 Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org> Commit-Queue: Harald Alvestrand <hta@webrtc.org> Cr-Commit-Position: refs/heads/main@{#36170}