Sounds like castouts, over to skonig@

joechen@, can you file feedback from Cast on this please?  To do that right-click on the Cast icon in the toolbar (after you've reproduced this issue) and choose to "Report an issue."  Make sure logs are included, and put your email address in the body of the report so that we can locate it quickly.  Please reply back here once that's done.

This looks like a crash in the WebRTC simulcast code.  sprang@ has been in this recently.

+milligan: Tim, does this sound like the WebRTC / Cast-to-Hangouts issue you mentioned to me the other day?

I've repro'd this. Seems to be trigger after renegotiation when screenshare simulcast experiment is turned on.
I'll roll it back while investigating.

I guess that means you no longer need me to file feedback?

No, I think I have what I need. Thanks!

Removing other labels as per c#11.

Thank you!

The following revision refers to this bug:
  https://chromium.googlesource.com/external/webrtc.git/+/fe627f30cbd3b4e0665237c7f309973cbf15e30b

commit fe627f30cbd3b4e0665237c7f309973cbf15e30b
Author: sprang <sprang@webrtc.org>
Date: Wed Mar 29 15:24:59 2017

Use simulcast for screenshare only in conference mode

Also, don't crash if InitEncode fails for vp8.

BUG= chromium:705505 

Review-Url: https://codereview.webrtc.org/2779163002
Cr-Commit-Position: refs/heads/master@{#17452}

[modify] https://crrev.com/fe627f30cbd3b4e0665237c7f309973cbf15e30b/webrtc/media/engine/webrtcvideoengine2.cc
[modify] https://crrev.com/fe627f30cbd3b4e0665237c7f309973cbf15e30b/webrtc/media/engine/webrtcvideoengine2_unittest.cc
[modify] https://crrev.com/fe627f30cbd3b4e0665237c7f309973cbf15e30b/webrtc/video/vie_encoder.cc
[modify] https://crrev.com/fe627f30cbd3b4e0665237c7f309973cbf15e30b/webrtc/video/vie_encoder_unittest.cc

Fix for crash bug was landed here: https://chromium.googlesource.com/external/webrtc/trunk/webrtc.git/+/90e3b7de4724e21e48f651a62e626fcc2b21b782
The code landed in chrome here: https://chromium.googlesource.com/chromium/src/+/6869066a6f9589b41fcb1857f25dfc9436ee69ef
...which was included from build 59.0.3057.0

The following revision refers to this bug:
  https://chromium.googlesource.com/external/webrtc.git/+/5bb66b6e65e11c5031893f731b722d0d7f06c09c

commit 5bb66b6e65e11c5031893f731b722d0d7f06c09c
Author: ilnik <ilnik@webrtc.org>
Date: Tue Apr 04 19:15:14 2017

Use simulcast for screenshare only in conference mode

Also, don't crash if InitEncode fails for vp8.

BUG= chromium:705505 
NOTRY=true
NOPRESUBMIT=true

Review-Url: https://codereview.webrtc.org/2779163002
Cr-Commit-Position: refs/heads/master@{#17452}
(cherry picked from commit fe627f30cbd3b4e0665237c7f309973cbf15e30b)

Review-Url: https://codereview.webrtc.org/2795043004
Cr-Commit-Position: refs/branch-heads/58@{#16}
Cr-Branched-From: f31969a584bcafe9406c214a9d4c3afb49d19650-refs/heads/master@{#16937}

[modify] https://crrev.com/5bb66b6e65e11c5031893f731b722d0d7f06c09c/webrtc/media/engine/webrtcvideoengine2.cc
[modify] https://crrev.com/5bb66b6e65e11c5031893f731b722d0d7f06c09c/webrtc/media/engine/webrtcvideoengine2_unittest.cc
[modify] https://crrev.com/5bb66b6e65e11c5031893f731b722d0d7f06c09c/webrtc/video/vie_encoder.cc
[modify] https://crrev.com/5bb66b6e65e11c5031893f731b722d0d7f06c09c/webrtc/video/vie_encoder_unittest.cc