How can I enable WebGL in QWebEngine 5.9 under Windows?

kitekat

I want to use WebGL in QtWebEngineWidgets.QWebEngineView under Windows with my Qt 5.9.2.

But when I try to load webglreport.com, in QWebEngineView it tells me, that "This browser supports WebGL 2, but it is disabled or unavailable."

How can I fix it?

Here's my code:

PyQt:

import os, sys
from PyQt5 import QtCore, QtGui, QtWidgets, QtWebEngineWidgets


if __name__ == '__main__':
    app = QtWidgets.QApplication(sys.argv)


   # app.setAttribute(QtCore.Qt.AA_UseOpenGLES)  # nothing happens, you can comment it out

    view = QtWebEngineWidgets.QWebEngineView()

    # view.settings().setAttribute(QtWebEngineWidgets.QWebEngineSettings.WebGLEnabled, True) # does not help too = (((

    view.load(QtCore.QUrl("http://webglreport.com/?v=2"))

    view.show()

    sys.exit(app.exec_())

    # And here WebGL Report  will tell me: "This browser supports WebGL 2, but it is disabled or unavailable."
    # How can I cope with it???

C++ Qt:

#include <QApplication>
#include <QtWebEngineWidgets/QWebEngineView>

#include <QUrl>
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QWebEngineView view;
    view.load(QUrl("http://webglreport.com/"));
    view.show();
    return a.exec();
}