[REG 5.5.1->5.x] Windows: WebEngine no longer supports webgl on Intel HD drivers

We have run into a regression in web browser where WebGL used to work on certain machines in 5.5, but no longer is supported in more recent releases.

We were able to reproduce this in the webengine browser demo that comes bundled by default. I can upload the specific binaries if that would be helpful, however we specifically didn't modify the demos at all, and were sure to use the examples provided with the specific QT version.

The page we used to test was: http://webglsamples.org/aquarium/aquarium.html

The results from that page varied between different QT versions:

• QT 5.5.1, x86 MSVC 2013 - Works as expected, frame rates seem to indicate proper hardware acceleration
• QT 5.6.1, x86 MSVC 2013 - Non functional, unable to create WebGL context.
• QT 5.7, x86 MSVC 2013 - Non functional, unable to create WebGL context.
• QT 5.7, x64 MSVC 2015 - Non functional, unable to create WebGL context.

I've attached full info on the display adapter, but the most salient part is that the adapter model is Intel(R) Iris(TM) Pro Graphics 5200 on a MacBook pro dual booted into Windows 7 professional.

I've seen sporadic other reports of other people running into the same issue; if I can get those hardware specs I'll attach them too.

Please let me know if there is any other information I could provide to help determine the cause / possible solutions.