gdk-frame-clock-refresh-info (frame-clock base-time)

frame-clock -- a gdk-frame-clock object
base-time -- an integer base time for determining a presentaton time

refresh-interval-return -- an integer with the determined refresh interval, or nil, a default refresh interval of 1/60th of a second will be stored if no history is present
presentation-time-return -- an integer with the next candidate presentation time after the given base time, 0 will be will be stored if no history is present

Using the frame history stored in the frame clock, finds the last known presentation time and refresh interval, and assuming that presentation times are separated by the refresh interval, predicts a presentation time that is a multiple of the refresh interval after the last presentation time, and later than base-time.