[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 4d27c40f06ea7f7e1be2c112e89a5635a9db3c3f..dde9c2f2dc6c82c44e6356e9e5bca622d8e7ae38 100644
--- a/src/heap/heap.h
+++ b/src/heap/heap.h
@@ -1255,13 +1255,8 @@ class Heap {
     return static_cast<intptr_t>(total);
   }
 
-  void UpdateNewSpaceAllocationCounter() {
-    new_space_allocation_counter_ = NewSpaceAllocationCounter();
-  }
-
-  size_t NewSpaceAllocationCounter() {
-    return new_space_allocation_counter_ + new_space()->AllocatedSinceLastGC();
-  }
+  inline void UpdateNewSpaceAllocationCounter();
+  inline size_t NewSpaceAllocationCounter();
 
   // This should be used only for testing.
   void set_new_space_allocation_counter(size_t new_value) {