Move it to include path of the rtp_rtcp module to indicate it is ok to include it outside of the module. Renamed to match the class it introduce and to reduce confusion with rtp_header_extensions.h Bug: webrtc:5565 Change-Id: Ic4b4e9f6b75cb9275e23539cd6e88632c1e7c8d2 Reviewed-on: https://chromium-review.googlesource.com/520947 Reviewed-by: Niels Moller <nisse@webrtc.org> Commit-Queue: Danil Chapovalov <danilchap@webrtc.org> Cr-Commit-Position: refs/heads/master@{#18402}