Revert of [heap] Fine-grained JSArrayBuffer tracking

src/heap/spaces.cc

Index: src/heap/spaces.cc
diff --git a/src/heap/spaces.cc b/src/heap/spaces.cc
index 94cdc86e3ee905de3047c31bc8835eb328ae66b0..cbf62bdb2d339166c2c293cb9267c8a560d6d3e0 100644
--- a/src/heap/spaces.cc
+++ b/src/heap/spaces.cc
@@ -518,7 +518,6 @@
   Bitmap::Clear(chunk);
   chunk->set_next_chunk(nullptr);
   chunk->set_prev_chunk(nullptr);
-  chunk->local_tracker_ = nullptr;
 
   DCHECK(OFFSET_OF(MemoryChunk, flags_) == kFlagsOffset);
   DCHECK(OFFSET_OF(MemoryChunk, live_byte_count_) == kLiveBytesOffset);
@@ -1040,11 +1039,6 @@
   if (old_to_old_slots_ != nullptr) ReleaseOldToOldSlots();
   if (typed_old_to_new_slots_ != nullptr) ReleaseTypedOldToNewSlots();
   if (typed_old_to_old_slots_ != nullptr) ReleaseTypedOldToOldSlots();
-
-  if (local_tracker_ != nullptr) {
-    delete local_tracker_;
-    local_tracker_ = nullptr;
-  }
 }
 
 static SlotSet* AllocateSlotSet(size_t size, Address page_start) {