SetTickRatePerMs  477 src/profile-generator.cc   top_down_.SetTickRatePerMs(actual_sampling_rate);
SetTickRatePerMs  478 src/profile-generator.cc   bottom_up_.SetTickRatePerMs(actual_sampling_rate);
SetTickRatePerMs  191 src/profile-generator.h   void SetTickRatePerMs(double ticks_per_ms);