Prevent zero-timestamps in captured_frame_.

ViECapturer::OnIncomingCapturedFrame can abort if two frames without a
timestamp are delivered at the same time (the same NTP timestamp is
generated). This currently causes captured_frame_ to be in a state
where timestamps (NTP time etc.) are set, but RTP timestamp is not. This
is an issue if the previous frame in captured_frame_ has yet to be
picked up by the capturer thread, as it will pick up captured_frame_ in
a state where the RTP timestamp has not been set.

BUG=chromium:480953
R=magjed@webrtc.org, stefan@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/45299004

Cr-Commit-Position: refs/heads/master@{#9094}
1 file changed