dcccda7e7c
Created a java wrapper for the callback OnAddTrack in this CL since it has been added to native C++ API The callback function is called when a track is signaled by remote side and a new RtpReceiver is created. The application can tell when tracks are added to the streams by listening to this callback. BUG=webrtc:6112 Review-Url: https://codereview.webrtc.org/2513723002 Cr-Commit-Position: refs/heads/master@{#15745}