[heap] New heuristics for incremental marking step size.

src/heap/heap.cc

Index: src/heap/heap.cc
diff --git a/src/heap/heap.cc b/src/heap/heap.cc
index 91b565e43b7a9025bf0c559e74cfaaa64bfac852..8d74e18e3c5f41ece38c6e8f66f84acc532ea820 100644
--- a/src/heap/heap.cc
+++ b/src/heap/heap.cc
@@ -115,7 +115,6 @@ Heap::Heap()
       inline_allocation_disabled_(false),
       total_regexp_code_generated_(0),
       tracer_(nullptr),
-      high_survival_rate_period_length_(0),
       promoted_objects_size_(0),
       promotion_ratio_(0),
       semi_space_copied_object_size_(0),
@@ -1276,11 +1275,6 @@ void Heap::UpdateSurvivalStatistics(int start_new_space_size) {
 
   double survival_rate = promotion_ratio_ + semi_space_copied_rate_;
   tracer()->AddSurvivalRatio(survival_rate);
-  if (survival_rate > kYoungSurvivalRateHighThreshold) {
-    high_survival_rate_period_length_++;
-  } else {
-    high_survival_rate_period_length_ = 0;
-  }
 }
 
 bool Heap::PerformGarbageCollection(
@@ -1317,13 +1311,6 @@ bool Heap::PerformGarbageCollection(
 
   int start_new_space_size = Heap::new_space()->SizeAsInt();
 
-  if (IsHighSurvivalRate()) {
-    // We speed up the incremental marker if it is running so that it
-    // does not fall behind the rate of promotion, which would cause a
-    // constantly growing old space.
-    incremental_marking()->NotifyOfHighPromotionRate();
-  }
-
   {
     Heap::PretenuringScope pretenuring_scope(this);