The following videos used in video_PlaybackPerf don't have audio.
2160_60_10s_600frames-2fd17338cb4d9cfd9d7299a108ca9145.vp9.webm
fallout4_1080_hfr.vp9.webm
traffic-3840x2160-cbcdda7d7143b3e9f8efbeed0c4157b5.vp9.webm

No audio changes chrome media playback behavior. It leads to measure an wrong dropped frames rate.
We should attach audio.

 

The following videos used in video_PlaybackPerf don't have audio.
VP9 1080P 60FPS: fallout4_1080_hfr.vp9.webm
VP9 4K 30FPS: traffic-3840x2160-cbcdda7d7143b3e9f8efbeed0c4157b5.vp9.webm
VP9 4K 60FPS: 2160_60_10s_600frames-2fd17338cb4d9cfd9d7299a108ca9145.vp9.webm

No audio changes chrome media playback behavior. It leads to measure an wrong dropped frames rate.
We should attach audio.