Reland of "[heap] Fine-grained JSArrayBuffer tracking"

src/heap/heap.cc

Index: src/heap/heap.cc
diff --git a/src/heap/heap.cc b/src/heap/heap.cc
index 3c21f777e5d3f378997d694df3d256645b2d2bf2..b710c5606e14f363d04710c448ff74d656752cdf 100644
--- a/src/heap/heap.cc
+++ b/src/heap/heap.cc
@@ -1626,8 +1626,6 @@ void Heap::Scavenge() {
 
   scavenge_collector_->SelectScavengingVisitorsTable();
 
-  array_buffer_tracker()->PrepareDiscoveryInNewSpace();
-
   // Flip the semispaces.  After flipping, to space is empty, from space has
   // live objects.
   new_space_.Flip();
@@ -1747,7 +1745,7 @@ void Heap::Scavenge() {
   // Set age mark.
   new_space_.set_age_mark(new_space_.top());
 
-  array_buffer_tracker()->FreeDead(true);
+  array_buffer_tracker()->FreeDeadInNewSpace();
 
   // Update how much has survived scavenge.
   IncrementYoungSurvivorsCounter(static_cast<int>(