It previously owned only the picture id and only in the WebRTC-VP8-Forced-Fallback-Encoder-v2 experiment. Moving responsibility to PayloadRouter ensures that both picture id and tl0 idx are continuous over codec changes, as required by the specs for VP8 and VP9 over RTP. Bug: webrtc:8830 Change-Id: Ie77356dfec6d1e372b6970189e4c3888451920e6 Reviewed-on: https://webrtc-review.googlesource.com/61640 Commit-Queue: Niels Moller <nisse@webrtc.org> Reviewed-by: Åsa Persson <asapersson@webrtc.org> Reviewed-by: Rasmus Brandt <brandtr@webrtc.org> Cr-Commit-Position: refs/heads/master@{#22448}