Preparation for cl https://webrtc-review.googlesource.com/c/src/+/150945. Bug: webrtc:8733 Change-Id: I98ed03a9117792f372d9c0fb5bc073879b4a18dc Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/151122 Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org> Commit-Queue: Niels Moller <nisse@webrtc.org> Cr-Commit-Position: refs/heads/master@{#29033}