UserAgent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.71 Safari/537.36

Steps to reproduce the problem:
1. create a packaged app which displays a webview using the webview tag.
2. on app/extension side, trigger chrome.desktopCapture.chooseDesktopMedia() and pass the streamId to the webview.
3. try to use the streamId inside the webview with GetUserMedia.

What is the expected behavior?
It should be possible to get access to the desktop Stream inside a webview somehow.

What went wrong?
The function chrome.desktopCapture.chooseDesktopMedia does not provide a possibility to create a valid streamId for a webview. There is no way to pass the second parameter (Tab), there are no Tabs inside a packaged app.

If second parameter is left out, the streamId is only valid on extension side, not inside an embedded webview (webview Tag).

It would be perfect if second parameter chrome.desktopCapture.chooseDesktopMedia could be a Tab OR WebView. Are there other ways to get desktopCapture to work inside a webview?

Did this work before? N/A 

Does this work in other browsers? N/A

Chrome version: 54.0.2840.71  Channel: stable
OS Version: 6.1 (Windows 7, Windows Server 2008 R2)
Flash Version: Shockwave Flash 23.0 r0