But keep #including scoped_ptr.h in .h files, so as not to break
WebRTC users who expect those .h files to give them rtc::scoped_ptr.
BUG=webrtc:5520
Review-Url: https://codereview.webrtc.org/1937693002
Cr-Commit-Position: refs/heads/master@{#12581}
Doesn't utilize the clock or any callbacks out of the receiver but
should still be useful to test input packet parsing.
BUG=webrtc:4771
R=danilchap@webrtc.org
Review URL: https://codereview.webrtc.org/1716143002 .
Cr-Commit-Position: refs/heads/master@{#11717}