public RectangleInt get_redraw_clip_bounds ()
Gets the bounds of the current redraw for this in stage pixel coordinates.
E.g., if only a single actor has queued a redraw then Clutter may redraw the stage with a clip so that it doesn't have to paint every pixel in
the stage. This function would then return the bounds of that clip. An application can use this information to avoid some extra work if it knows
that some regions of the stage aren't going to be painted. This should only be called while the stage is being painted. If there is no current
redraw clip then this function will set
clip to the full extents of the stage.
Return location for the clip bounds