[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 fd788cdbe991c413d00e7ee2ce74ca9b4a7a2371..2da975b954c7b71d27973bb6e6ad68fe168bf74f 100644
--- a/src/heap/heap.h
+++ b/src/heap/heap.h
@@ -805,11 +805,11 @@ class Heap {
   }
 
   int64_t amount_of_external_allocated_memory() {
-    return amount_of_external_allocated_memory_;
+    return amount_of_external_allocated_memory_.Value();
   }
 
   void update_amount_of_external_allocated_memory(int64_t delta) {
-    amount_of_external_allocated_memory_ += delta;
+    amount_of_external_allocated_memory_.Increment(delta);
   }
 
   void DeoptMarkedAllocationSites();
@@ -1974,10 +1974,10 @@ class Heap {
 
   // The amount of external memory registered through the API kept alive
   // by global handles
-  int64_t amount_of_external_allocated_memory_;
+  base::AtomicNumber<intptr_t> amount_of_external_allocated_memory_;
 
   // Caches the amount of external memory registered at the last global gc.
-  int64_t amount_of_external_allocated_memory_at_last_global_gc_;
+  intptr_t amount_of_external_allocated_memory_at_last_global_gc_;
 
   // 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.