Websurfaces cause frame count halving with vsync enabled.

[panmarco83]

If janus is launched with vsync enabled (not using -novsync) into a room with a websurface in it or open a private web surface, the frame count halves (from 60 to 30 fps) (internal fps counter).
This is observable by opening the performance monitor and also just frame drops or stuttering "ingame".
Something with the websurfaces is causing janus to render half as fast.
The stranger thing is that nvidia Enable Graphics API Visual Indicator shows a steady 60 fps except when loading the room.