I suspect the problem is with the gvc frontend page that hotrod app hosts in its webview. If chrome detects wrong screen size, the UI will simply be clipped rather than scrolling a bit.

Possibly related from our feedback reports:
http://b/35600969

Marking Restrict-View-Google due to b/ link.

Thanks Denis.
1) Now that we have bugs on both sides, which should be mark as the master bug for this issue ?
2) If it is crbug, then I would recommend removing the restriction for transparency. Just having b/ link in here may not be super confidential. And if this is really the master bug, lets remove that comment as it may not be very helpful either way. Instead just put in a feedback report id here.

The affected TV is an LG 55UX340C but customer is seeing the issue across numerous devices. At this moment it seems to have affected every CFM they have.

CHROME VERSION=56.0.2924.101

System logs: 
https://drive.google.com/drive/folders/0ByMyi5nFZNn6UlFnc2YtSnJXVUU?usp=sharing

We are able to repro with M58 but not with latest M53 (8530.96.0) stable with couple different monitors. Have not tried with M57/M56/M55 today but we tested M56 and M57 last week and did not see this issue.


Logs attached: https://pantheon.corp.google.com/storage/browser/chromiumos-test-logs/bugfiles/cr/694571/

Panther (issue seen)
9202.0.0 / 58.0.3011.0
App version: Google Hangouts 1.3.98.0
WCS: 20170208.05_p4


Zako (issue not seen)
8530.96.0 / 53.0.2785.154
App version: Google Hangouts 1.3.98.0
WCS: 20170208.05_p4



Is there a way for us to try repro with an older version of the hotrod app?

Lots of b/ links in other open bugs. That ship has sailed. No need to lock this one down.

GVC frontend site uses a lot of height:100% in the DOM tree. When the problem happens, starting a level of the div hierarchy, the height is calculated to something more than 100% of the parent (and the screen).

I thought we had the conference control and video thumb overlaied on top of the main video. But it seems they are laied out vertically one after another when the problem happens.

The problem could be either a css style change in GVC or chrome/blink layout code change. I will try to see whether I could bisect it to a chrome/blick change.

dsunkara@ was able to narrow it down to the following builds..

Hotrod app: 1.3.98.0
WCS: 20170209.05_p2

Good
9000.83.0 / 56.0.2924.89


Bad:
9000.87.0 / 56.0.2924.101


Note, we tested 9000.87.0 last week but did not see this issue. Could be that the WCS or hotrod app versions were different last week.

Issue 693722 seems related. Blink CL is reverted on trunk and merged to M56 and M57. Let me sync and see if that helps.

fwiw I can't repro it on ToT (which is not the case with a build from last week)

Is this a dupe of http://crbug.com/693722?

Confirmed that the blink revert fixed the issue. Merge to 693722