BackgroundCache (js/ui/background.js) does not remove unused file monitors
- in Looking Glass enter: "Main.overview._bgManagers[0]._backgroundSource._backgrounds[0]._cache._fileMonitors", then click on result "[object Object]" to show active file monitors
- quit from Looking Glass
- change wallpaper image several times (choose different files)
- do step 1., will show increased list of active file monitors