4da058c0dd
Create the RTCRtpReceiverDelegate which is a wrapper over webrtc::RtpReceiverObserverInterface. The callback will be called whenever the first rtp packet is received. Related CL: https://codereview.webrtc.org/2531333003/ BUG=webrtc:6742 Review-Url: https://codereview.webrtc.org/2641923003 Cr-Commit-Position: refs/heads/master@{#16501}