partial
xkb_types "chromebook" {
    type "CHROMEBOOK" {
        modifiers = Control+Alt+Shift+LevelThree;
        map[None] = Level1;
        map[Shift] = Level2;
        map[LevelThree] = Level3;
        map[Shift+LevelThree] = Level4;
        map[Control+LevelThree] = Level3;
        map[Control+Shift+LevelThree] = Level4;
        map[Control+Alt] = Level5;
        preserve[Shift] = Shift;
        preserve[Shift+LevelThree] = Shift;
        preserve[Control] = Control;
        preserve[Control+LevelThree] = Control;
        preserve[Control+Shift+LevelThree] = Control+Shift;
        level_name[Level1] = "Base";
        level_name[Level2] = "Shift";
        level_name[Level3] = "LevelThree";
        level_name[Level4] = "Shift LevelThree";
        level_name[Level5] = "Ctrl+Alt";
    };
};