Launching with -VR will pick non-native display resolution for Vive/SteamVR

• Running with -game will run game at native fullscreen resolution 1920x1080. (checking with r.setres)
• Running with -game -vr will run game in VR but resolution is 1280x720. (checking with r.setres)

This makes it looks like screen percentage is off, but in fact is correct.

Setup:
Have Showdown Sample (or a sample you can notice visual fidelity)

1. Open Showdown with -Game -VR
2. Look through headset

Result: Notice the reduced fidelity, compared to running with -game , and then typing 'stereo on' in console.