SurvivalRateTrend 1930 src/heap.h       SurvivalRateTrend previous_survival_rate_trend_;
SurvivalRateTrend 1931 src/heap.h       SurvivalRateTrend survival_rate_trend_;
SurvivalRateTrend 1933 src/heap.h       void set_survival_rate_trend(SurvivalRateTrend survival_rate_trend) {
SurvivalRateTrend 1939 src/heap.h       SurvivalRateTrend survival_rate_trend() {