e), and no
  additional time duration restriction will be applied.

  MOZ_PROFILER_STARTUP_INTERVAL=<1..%d>
  If MOZ_PROFILER_STARTUP is set, specifies the sample interval,
  measured in milliseconds, when the profiler is first started.
  If unset, the platform default is used.

  MOZ_PROFILER_STARTUP_FEATURES_BITFIELD=<Number>
  If MOZ_PROFILER_STARTUP is set, specifies the profiling features, as
  the integer value of the features bitfield.
  If unset, the value from MOZ_PROFILER_STARTUP_FEATURES is used.

  MOZ_PROFILER_STARTUP_FEATURES=<Features>
  If MOZ_PROFILER_STARTUP is set, specifies the profiling features, as
  a comma-separated list of strings.
  Ignored if  MOZ_PROFILER_STARTUP_FEATURES_BITFIELD is set.
  If unset, the platform default is used.

    Features: (x=unavailable, D/d=default/unavailable,
               S/s=MOZ_PROFILER_STARTUP extra default/unavailable)