Introduce an option to do regular new space growing for a while

src/heap/heap.cc

Index: src/heap/heap.cc
diff --git a/src/heap/heap.cc b/src/heap/heap.cc
index 9785be0b91d59785a5b38a6da7ac38006ed8bfa2..8c76cfb8d1f1f21a6bfaea0e07c0d29845aac678 100644
--- a/src/heap/heap.cc
+++ b/src/heap/heap.cc
@@ -62,6 +62,7 @@ Heap::Heap()
       max_semi_space_size_(8 * (kPointerSize / 4) * MB),
       initial_semispace_size_(Page::kPageSize),
       target_semispace_size_(Page::kPageSize),
+      scavenges_before_grow_(0),
       max_old_generation_size_(700ul * (kPointerSize / 4) * MB),
       max_executable_size_(256ul * (kPointerSize / 4) * MB),
       // Variables set based on semispace_size_ and old_generation_size_ in
@@ -1570,6 +1571,12 @@ void Heap::Scavenge() {
   IncrementYoungSurvivorsCounter(static_cast<int>(
       (PromotedSpaceSizeOfObjects() - survived_watermark) + new_space_.Size()));
 
+  if (scavenges_before_grow_ > 0) {
+    if (--scavenges_before_grow_ == 0) {
+      new_space()->set_grow_to_target_capacity(true);
+    }
+  }
+
   LOG(isolate_, ResourceEvent("scavenge", "end"));
 
   gc_state_ = NOT_IN_GC;
@@ -5059,6 +5066,8 @@ bool Heap::ConfigureHeap(int max_semi_space_size, int max_old_space_size,
 
   target_semispace_size_ = Max(initial_semispace_size_, target_semispace_size_);
 
+  scavenges_before_grow_ = Max(FLAG_scavenges_before_grow, 0);
+
   // The old generation is paged and needs at least one page for each space.
   int paged_space_count = LAST_PAGED_SPACE - FIRST_PAGED_SPACE + 1;
   max_old_generation_size_ =
@@ -5241,6 +5250,9 @@ bool Heap::SetUp() {
     return false;
   }
   new_space_top_after_last_gc_ = new_space()->top();
+  if (scavenges_before_grow_ <= 0) {
+    new_space()->set_grow_to_target_capacity(true);
+  }
 
   // Initialize old pointer space.
   old_pointer_space_ = new OldSpace(this, max_old_generation_size_,