So, I ran into this with Everspace where you need the ESC key on PC to navigate the menus. In this case, in AC:Unity when you are in the options menu it shows at the bottom "[ESC] PREVIOUS / Controls". Normally this will back you up one level in the menu. But the ESC key instead pops up the Back to Game or Exit Game menu in Chrome.
EDIT:
The Duck Duck Go Essential extension was somehow messing with this feature. Once I removed that extension it works as it should in all games I've tested.