8e93806453
We need to access the visible children of a page in inside vfunc_allocate(), and since getting those children is quite slow (it involves iterating over all the children of the actor) let's avoid that and cache the array instead. This reduces average time spent in vfunc_allocate() of the iconGrid from 1.6 ms down to 1.4 ms. Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1713>