ce4aef16ee
This is a re-land of https://codereview.webrtc.org/1353263005/ which was reverted because of perf-regressions. Changes since that CL: * Change LayerFilteringTransport to send a padding packet instead of dropping it for data that should be filtered out. This prevents confusion due to changed sequence numbers. * Changed timing of stats poller thread in VideoAnalyzer. Startup was racy wrt initializion of send_stream_. * Minor formatting issues. PERF NOTE: This change will affect some performance numbers slightly. In particular, {encode_frame_rate, encode_time_ms, encode_usage_percent, media_bitrate_bps} will change due to timing of the measurements. BUG= R=pbos@webrtc.org TBR=mflodman@webrtc.org Review URL: https://codereview.webrtc.org/1412233003 Cr-Commit-Position: refs/heads/master@{#10483}