Reland "[heap] Fine-grained JSArrayBuffer tracking"

src/heap/heap.h

Index: src/heap/heap.h
diff --git a/src/heap/heap.h b/src/heap/heap.h
index 3692823eeab47c8a09ed3ac0cc7b20b9d6faef30..8430c955659b8643db0dd1e0f35bc2e4dd775ac9 100644
--- a/src/heap/heap.h
+++ b/src/heap/heap.h
@@ -822,6 +822,16 @@ class Heap {
     amount_of_external_allocated_memory_ += delta;
   }
 
+  void update_amount_of_external_allocated_freed_memory(intptr_t freed) {
+    amount_of_external_allocated_memory_freed_.Increment(freed);
+  }
+
+  void account_amount_of_external_allocated_freed_memory() {
+    amount_of_external_allocated_memory_ -=
+        amount_of_external_allocated_memory_freed_.Value();
+    amount_of_external_allocated_memory_freed_.SetValue(0);
+  }
+
   void DeoptMarkedAllocationSites();
 
   bool DeoptMaybeTenuredAllocationSites() {
@@ -1356,10 +1366,6 @@ class Heap {
   void RegisterNewArrayBuffer(JSArrayBuffer* buffer);
   void UnregisterArrayBuffer(JSArrayBuffer* buffer);
 
-  inline ArrayBufferTracker* array_buffer_tracker() {
-    return array_buffer_tracker_;
-  }
-
   // ===========================================================================
   // Allocation site tracking. =================================================
   // ===========================================================================
@@ -1997,6 +2003,8 @@ class Heap {
   // Caches the amount of external memory registered at the last global gc.
   int64_t amount_of_external_allocated_memory_at_last_global_gc_;
 
+  base::AtomicNumber<intptr_t> amount_of_external_allocated_memory_freed_;
+
   // This can be calculated directly from a pointer to the heap; however, it is
   // more expedient to get at the isolate directly from within Heap methods.
   Isolate* isolate_;
@@ -2235,8 +2243,6 @@ class Heap {
 
   StrongRootsList* strong_roots_list_;
 
-  ArrayBufferTracker* array_buffer_tracker_;
-
   // The depth of HeapIterator nestings.
   int heap_iterator_depth_;