Returns the frame counter for the oldest frame available in history.
GdkFrameClock internally keeps a history of GdkFrameTimings
objects for recent frames that can be retrieved with
[method@Gdk.FrameClock.get_timings]. The set of stored frames
is the set from the counter values given by
[method@Gdk.FrameClock.get_history_start] and
[method@Gdk.FrameClock.get_frame_counter], inclusive.
Returns the frame counter for the oldest frame available in history.
GdkFrameClock internally keeps a history of GdkFrameTimings objects for recent frames that can be retrieved with [method@Gdk.FrameClock.get_timings]. The set of stored frames is the set from the counter values given by [method@Gdk.FrameClock.get_history_start] and [method@Gdk.FrameClock.get_frame_counter], inclusive.