These are tests using a real physical webcam. The error message "VIDIOC_STREAMON failed" indicates that it fails while trying to open the camera at https://cs.chromium.org/chromium/src/media/capture/video/linux/v4l2_capture_delegate.cc?q=VIDIOC_STREAMON+failed&l=503


The first failure I could find is 
https://ci.chromium.org/buildbot/chromium.webrtc/Linux%20Tester/37162

I could not find any obvious CLs in this or the previous 10 builds that should have made any difference here. https://chromium-review.googlesource.com/c/chromium/src/+/999296 enabled some tests for OS_LINUX, but it don't think these tests are actually run on this bot.

My current best guess is that there is an issue with the webcam or bot. 

phoglund@ or jansson@, could we attempt to reboot/reset/reconnect the bot/webcam on chromium.webrtc Linux Tester and see if this resolves the issue?