If for some reason capture timestamp is unset, the default value of 0 would be passed to RtcpSender. This will cause rtp timestamps to grow at double the rate in Sender Reports because it has time since the last frame capture as a term. Bug: none Change-Id: I2fe09dabef6b0957fb504deaa06393dedc4a9e70 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/162481 Reviewed-by: Danil Chapovalov <danilchap@webrtc.org> Commit-Queue: Ilya Nikolaevskiy <ilnik@webrtc.org> Cr-Commit-Position: refs/heads/master@{#30105}