Recreating icons on every style change -- like hover, can have
disasterous effects. Not only is the quick creation/destruction of
the actors bad, but adding/removing actors at runtime queues many
relayouts, which makes the whole system slower as a lot of unnecessary
reallocations are figured out.
While an optimization was here before, it was broken because it
broke high-contrast themes. Connect explicitly to the texture cache
to know when the icon theme has changed, instead of removing a valuable
optimization.
https://bugzilla.gnome.org/show_bug.cgi?id=672941
429f9e1d15