This excludes these frames from being counted as dropped by encoder. Also fix bitrate projected distribution for vp9 svc for outliers detection. Bug: webrtc:8497 Change-Id: Id37487456170c61e2323a660668f0c319ea5831d Reviewed-on: https://webrtc-review.googlesource.com/21223 Commit-Queue: Ilya Nikolaevskiy <ilnik@webrtc.org> Reviewed-by: Erik Språng <sprang@webrtc.org> Cr-Commit-Position: refs/heads/master@{#20632}