This is used to allow mocking in tests in later CLs. Bug: None Change-Id: Id610471efb4a86c903530585dd4ee2fa1d1ea5bc Reviewed-on: https://webrtc-review.googlesource.com/70880 Commit-Queue: Sebastian Jansson <srte@webrtc.org> Reviewed-by: Niels Moller <nisse@webrtc.org> Cr-Commit-Position: refs/heads/master@{#22941}