OptionallabelA label prepended to every console message when log is true.
Defaults to 'createPerfTimer'.
OptionallogWhen true, each PerfTimer.lap and PerfTimer.stop call prints a
formatted line to console.log. Defaults to false.
OptionalonCalled after each PerfTimer.lap with the PerfTimerLap that was just recorded. Errors thrown by this callback are silently swallowed so they never propagate to the caller.
OptionalonCalled each time PerfTimer.stop is invoked with the PerfTimerResult snapshot. Errors thrown by this callback are silently swallowed so they never propagate to the caller.
Options accepted by createPerfTimer.