In general, all clients / service providers need is dbus::Bus, at the end, its just a socket and I don't really see why high level classes need to create DBusManager and pass it around. Previous approach moved dbus manager all way up to RuntimeContext which IMO is bad. If we would need to integrate xwalk with weekeyboard / ibus, it would be quite difficult to grab RuntimeContext from InputMethod classes, thus I think we need to decouple dbusmanager from core xwalk runtime classes.

@cmarcelo what do you think?