Missing important detail: I can't share application window of another window of Chrome.

Tested the issue on chrome reported version 65.0.3325.181 using Windows-10 with steps mentioned below:
1) Launched chrome reported version and navigated to URL: http://appear.in with two users(user-1 & user-2) into same room
2) From the user-1 clicked on share screen and selected the window-1(Application window) which need to shared
3) Able to see window-1(shared screen) on user-2, -- able to see all opened tabs
4) Clicked on three dot menu (top right corner) > opened "New Window"(say window-2) on user-1, but unable to see the newly opened window-2 on user-2 system
Observations: Tested the issue on latest chrome version 67.0.3386.0 and 60.0.3072.0, seen the same behaviour as mentioned above

@Reporter: Please find the above steps and observations and let us know if you are also seeing the same behaviour, provide your feedback on it which helps in further triaging it. 

Note: As ET team doesn't have camera access on reported OS (windows-7), hence forwarding it to inhouse team for further investigation on this issue. Hence adding TE-NeedsTriageFromHYD label, can anyone from the inhouse team have a look at this issue.

Thanks! 

Unable to test this issue Win 7 desktop with no access no access to Webcam & microphone,hence adding TE-NeedsTriageFromMTV label for further triage from MTV on Win7 laptop

Thank You...

Unable to reproduce the issue on Windows 7 with chrome #65.0.3325.181

SetUp:
1. Windows 7 Desktop with WebCam access
2. Debian Rodete Laptop

Steps Followed:
1. On Windows machine create a chatroom in https://appear.in/xxxxx
2. On Debian machine, log into chat room as two users
3. On Windows machine, click on Sharescreen
4. Select Entire Screen
5. Select Application Window

Observations:
4A. On sharing Full screen, the data is correctly transmitted in the Debian machine
5A. On sharing application window, the data is correctly transmitted in the Debian machine

Attaching the screen-cast for reference.

stiv.yakovenko@ Could you please look into it and let us know your observations

Deleted: 827861.mp4 20.0 MB

827861.mp4 20.0 MB Download

I am using windows 7. I don't have deviant machine.

Thank you for providing more feedback. Adding the requester to the cc list.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

As per Comment#4 & 8 we are unable to reproduce the issue from our end, hence removing Needs-Bisect label and requesting someone from the Blink>GetUserMedia>Desktop team please have a look at this issue.

Thanks!

As per comment #13, adding label TE-NeedsTriageHelp for further investigation from dev team.
Thanks...!!

This is WAI on Win7 that you can't share application window of another window of Chrome.

Chrome can't support printwindow/bitblt as it's hw accelerated nature.
On Windows10, which support DirectX capture, it can be shared as long as it's on top of the desktop.

What is WAI? Didn't manage to find any info on the net.

It seems that braveyao is wrong. If I take Version 61.0.3153.0 on Windows7, I can share its own windows. I will try to bisect.

I've done some more (superficial testing):

 65.0.3290.0 (chromium) works
 65.0.3325.181 (chrome)  doesn’t work
 66.0.3359.139 (chrome Official Build) (64-bit) doesn’t work
 68.0.3397.0 (Developer Build) (64-bit) (chromium) works

may be the rootcause is some bug in the installer?

Sharing another window of Browser also works in Yandex browser, which is derivative of chromium also.

WAI = Work As Intended.

Yes Chrome can share its own windows, but it can't share another Chrome window. For example, Chrome Stable can't share Canary's window. 

Well, why then it works on Chromium in other versions? 

You mean other browsers based on chromium?
That depends how they do their own implementation(rendering or Bitblt supporting, etc.).  Like we can share FireFox window too.

You can download Chromium (i've listed versions) or Yandex browser and they can share their own windows on W7.

OK, so it's Chrome own window to be shared on Win7. Then this should work. 
From your comments #19, it looks it doesn't work in M65/66 and works again in M68. Then I guess probably something wrong has been fixed in later Chrome version.

One known problem that Chrome can't share its own window is the HW accelerated compositing is disabled for some reason. You can check it by chrome://gpu.
Also some new working will guarantee that Chrome window capture will be fine even with SW compositing. 

Since it works again, so it's still fine.

Ok, this is a real rootcause! I've disable HW acceleration on my browser and screen capture stopped working. I had to do that because some videos were not played correctly. May be user should be notified at least about broken screenshare in case of sharing or disabled acceleration?

As mentioned in #25, it won't depend on HW accelerated compositing totally soon. Stay tuned :)