The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/platform/tast-tests/+/40cb081f6ae71be191546d3b866ddf2e6722a9e4

commit 40cb081f6ae71be191546d3b866ddf2e6722a9e4
Author: Keiichi Watanabe <keiichiw@chromium.org>
Date: Mon Nov 19 04:44:51 2018

Revert "video.WebRTC*: Remove "informational" attribute"

This reverts commit d8ff4b33c655a8b9daa279f63d8fd8fe600db9fc.

Reason for revert: Failing on bob-paladin  crbug.com/906493 

Original change's description:
> video.WebRTC*: Remove "informational" attribute
>
> Remove "informational" attributes from
> - tast.video.WebRTCCamera,
> - tast.video.WebRTCPeerConnCameraH264 and
> - tast.video.WebRTCPeerConnCameraVP8
> so that these tests will run in Chrome CQ and Chrome OS CQ.
>
> BUG= chromium:900857 
> TEST=tast run <amd64-generic VM> video.WebRTC*
>
> Change-Id: I5f0220edab5ab6ae9b49a0bdb51f9fc206f937f8
> Signed-off-by: Keiichi Watanabe <keiichiw@chromium.org>
> Reviewed-on: https://chromium-review.googlesource.com/1312537
> Reviewed-by: Dan Erat <derat@chromium.org>

Bug:  chromium:900857 ,  chromium:906493 
Change-Id: I143af696352c8579938a04d265a588ad7be7978b
Reviewed-on: https://chromium-review.googlesource.com/c/1341290
Tested-by: Keiichi Watanabe <keiichiw@chromium.org>
Trybot-Ready: Keiichi Watanabe <keiichiw@chromium.org>
Reviewed-by: Shuhei Takahashi <nya@chromium.org>

[modify] https://crrev.com/40cb081f6ae71be191546d3b866ddf2e6722a9e4/src/chromiumos/tast/local/bundles/cros/video/webrtc_camera.go
[modify] https://crrev.com/40cb081f6ae71be191546d3b866ddf2e6722a9e4/src/chromiumos/tast/local/bundles/cros/video/webrtc_peer_conn_camera_vp8.go
[modify] https://crrev.com/40cb081f6ae71be191546d3b866ddf2e6722a9e4/src/chromiumos/tast/local/bundles/cros/video/webrtc_peer_conn_camera_h264.go

This problem seems to be caused by a broken DUT. So, I created Issue 906514.

The faulty bob device was excluded by Issue 906514 and WebRTC tests start running on CQ again.
It looks stable. So, let me close this issue.