background-content: ceilf the actor size instead of roundf
We want the bounding box so ceilf
seems more appropriate. It was
only written using roundf
before as a workaround for inaccuracies
coming out of clutter_actor_get_transformed_size
that would have
tricked ceilf
into landing on the wrong integer. But that's since
been fixed by 67cc60cb so we can use ceilf
now.