Switch to fullscreen never occurs when running webplayer build in IE10.

Windows 8 IE10.

Repro Steps:

1. Get latest manualruntimetest project
2. Import into 4.0.0rc3
3. Build webplayer and run in IE10
4. Observe fullscreen is never enter automatically
5. All tests are ran twice in Windowed mode

Desired outcome: Fullscreen to switch automatically

Fullscreen can be achieved if you enable context menu and right click -> go fullscreen.