There seems to be a bug when opening the camera via input tag in a 'Homescreen App'. After a fresh start the camera works fine, but after putting the App in the background and bring it back again, the camera only shows a black screen. Only a complete restart of the App solves the 'black screen' problem. Sample with Instructions: https://storage.googleapis.com/ios-pwa/index.html
<rdar://problem/56271398>
The fix for this issue was needed outside the WebKit project, therefore this is being resolved as 'Moved'. This should now be fixed in shipping software.