I don't really understand the issue, on Win 7, I see the native controls and if I change the volume of the video, it's reflected in the controls.
Created attachment 8811381 [details] Screen clips of the bug (left) and correct display result.(right)
Ah ok, the link you provided in comment #0 is the testcase (with the issue). I thought it was just a demo page you used to produce your own testcase. Indeed, with http://ettingerengineering.com/newsite/video_test.html I can't change the volume. The control is stuck.