window: throttle resizing to the main surface
window: throttle resizing to the main surface

In case a toytoolkit application manages to schedule resizes constantly,
throttle them to the main surface display.

When resizing, all surfaces are updated synchronously, so it also makes
sense to synchronize on the main surface's frame callback particularly.
Rendering any faster will not make sense.

Signed-off-by: Pekka Paalanen <6c0263d81461c956d504307112a4ce25eaacc3d1@gmail.com>

kwm81/weston,sir-murray/weston,giucam/weston,xorgy/weston,udoprog/weston,giucam/weston,Fantu/compositor-spice,mchalupa/weston,Gnurou/weston,krezovic/weston,mchalupa/weston,eyolfson/weston,xorgy/weston,jonnylamb/weston,eyolfson/weston,Fantu/compositor-spice,Tarnyko/weston-xdg_surface_present,kwm81/weston,sir-murray/weston,jonnylamb/weston,Fantu/compositor-spice,krezovic/weston,Tarnyko/weston-xdg_surface_present,udoprog/weston,Gnurou/weston