Code review comment for lp:~afrantzis/mir/vt-switching

> I kept thinking the pause/resume for the platform and the display could be
> consilidated, however I think its ok as it is

This is doable, although less explicit, but on second thought I prefer it this way too.
We can also move register_pause_resume_handlers() to mg::Display too, thus leaving the mg::Platform interface unchanged.