Obsolete nonproduct flag ProfilerCheckIntervals

ProfilerCheckInterval: "Collect and print information on spacing of profiler ticks"

In reality it samples the time it takes for the WatcherThread to sleep, run its tasks, and then prints out a rather non-descript histogram on process exit (ignoring the last interval, because why not).

Is this a remnant from the now-removed flat profiler? Either way it seems quite useless by itself and should be up for removal.