While intercepting key events on Windows with our low-level hook, we track repeat state internally in the hook.  This is required because intercepting the key event at that level prevents the OS from seeing the event and tracking the keypress state accurately.

One scenario where this is an issue is in the fullscreen -> window mode scenario.  The user presses Esc and holds it down which causes a series of KeyDown w/ repeat flag messages to be sent to the web site.  When fullscreen exits, the Esc key is still held down but the OS is seeing it for the first time.  Since it isn't being tracked yet, the OS does not mark the Esc key event as a repeat.

This is probably not a huge issue, however other platforms don't have this behavior so we should try to address this and make key handling consistent across platforms.