The changes in the master clock and the repaint cycle have been
changed, and broke the way the test for the Text actor cache of
PangoLayouts forces a redraw.
We have to call clutter_actor_paint() on the Stage embedding the
Text actor we want to test; this is kinda fugly because if the
Layout has changed it will end up causing a reallocation cycle
in the middle of the Text actor paint. Since it's a test case,
and since forcing redraws is a bit of a hack as well, we can
close both our eyes on that.