Together with RtpDepacketizer refactoring that would reduce number of memcpy while handling an rtp packet Bug: webrtc:11152 Change-Id: I6f4e09c93af5e2a9314967a15eac8ced57ec712e Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/161087 Reviewed-by: Philip Eliasson <philipel@webrtc.org> Reviewed-by: Erik Språng <sprang@webrtc.org> Commit-Queue: Danil Chapovalov <danilchap@webrtc.org> Cr-Commit-Position: refs/heads/master@{#29985}