Only listen to the fullscreen-events of one of the different vendor
Only listen to the fullscreen-events of one of the different vendor

Without doing this, it can happen that the handlers are called via the 'fullscreenchange' and 'webkitfullscreenchange' event when using the 'Fullscreen-API-Polyfill' (https://github.com/neovov/Fullscreen-API-Polyfill). So it is best to only listen to one of the events, otherwise the handler may be called several times which lead to nothing being presented.
borismus/webvr-polyfill,immersive-web/webvr-polyfill,marciot/webvr-polyfill,borismus/webvr-polyfill,marciot/webvr-polyfill,jsantell/webvr-polyfill,immersive-web/webvr-polyfill,bkkl/bkkl.github.io,bkkl/bkkl.github.io,jsantell/webvr-polyfill