Revert "[heap] Optimize NewSpace::AllocatedSinceLastGC"

src/heap/heap.h

Index: src/heap/heap.h
diff --git a/src/heap/heap.h b/src/heap/heap.h
index 5599f1b4ff9e9cdfede0fafe7ff97e448ff23621..4b542f87b5ef0b3b9837f37a27cdd7210fdf7c2a 100644
--- a/src/heap/heap.h
+++ b/src/heap/heap.h
@@ -1258,8 +1258,13 @@ class Heap {
     return static_cast<intptr_t>(total);
   }
 
-  V8_INLINE void UpdateNewSpaceAllocationCounter();
-  V8_INLINE size_t NewSpaceAllocationCounter();
+  void UpdateNewSpaceAllocationCounter() {
+    new_space_allocation_counter_ = NewSpaceAllocationCounter();
+  }
+
+  size_t NewSpaceAllocationCounter() {
+    return new_space_allocation_counter_ + new_space()->AllocatedSinceLastGC();
+  }
 
   // This should be used only for testing.
   void set_new_space_allocation_counter(size_t new_value) {