Move global pretenuring flag check to ShouldGloballyPretenure().

src/heap.h

Index: src/heap.h
diff --git a/src/heap.h b/src/heap.h
index b24b0b3608344ffba6177e42df6edf3c02f217e2..c3ff84c20e952d995e99fc1112a2e0bb7cfdf253 100644
--- a/src/heap.h
+++ b/src/heap.h
@@ -1546,7 +1546,12 @@ class Heap {
   // Predicate that governs global pre-tenuring decisions based on observed
   // promotion rates of previous collections.
   inline bool ShouldGloballyPretenure() {
-    return new_space_high_promotion_mode_active_;
+    return FLAG_pretenuring && new_space_high_promotion_mode_active_;
+  }
+
+  // This is only needed for testing high promotion mode.
+  void SetNewSpaceHighPromotionModeActive(bool mode) {
+    new_space_high_promotion_mode_active_ = mode;
   }
 
   inline PretenureFlag GetPretenureMode() {