Revert of [heap] Pass a force_promotion flag to the evacuation routine in the scavenger.

src/heap/heap.h

Index: src/heap/heap.h
diff --git a/src/heap/heap.h b/src/heap/heap.h
index 150647fbc7c0d2ad31dcc8a36ceaa8e01e54b833..7f9275a842a8d2a770c767ac210548511e665cc6 100644
--- a/src/heap/heap.h
+++ b/src/heap/heap.h
@@ -301,10 +301,7 @@
 class ScavengeJob;
 class WeakObjectRetainer;
 
-enum PromotionMode { FORCE_PROMOTION, DEFAULT_PROMOTION };
-
-typedef void (*ObjectSlotCallback)(HeapObject** from, HeapObject* to,
-                                   PromotionMode mode);
+typedef void (*ObjectSlotCallback)(HeapObject** from, HeapObject* to);
 
 // A queue of objects promoted during scavenge. Each object is accompanied
 // by it's size to avoid dereferencing a map pointer for scanning.