The two timestamps, rtp time and corresponding system time, are always used together, for audio/video sync. The new method reads both timestamps, without releasing a lock in between. Ensures that the caller gets values corresponding to the same packet. Bug: webrtc:7135 Change-Id: I25bdcbe9ad620016bfad39841b339c266efade14 Reviewed-on: https://webrtc-review.googlesource.com/4062 Commit-Queue: Niels Moller <nisse@webrtc.org> Commit-Queue: Stefan Holmer <stefan@webrtc.org> Reviewed-by: Stefan Holmer <stefan@webrtc.org> Reviewed-by: Fredrik Solenberg <solenberg@webrtc.org> Reviewed-by: Danil Chapovalov <danilchap@webrtc.org> Cr-Commit-Position: refs/heads/master@{#20120}