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

src/heap/scavenger.h

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_HEAP_SCAVENGER_H_
 #define V8_HEAP_SCAVENGER_H_
 
 #include "src/heap/objects-visiting.h"
 #include "src/heap/slot-set.h"
 
 namespace v8 {
 namespace internal {
 
 typedef void (*ScavengingCallback)(Map* map, HeapObject** slot,
-                                   HeapObject* object);
+                                   HeapObject* object, bool force_promotion);
 
 class Scavenger {
  public:
   explicit Scavenger(Heap* heap) : heap_(heap) {}
 
   // Initializes static visitor dispatch tables.
   static void Initialize();
 
   // Callback function passed to Heap::Iterate etc.  Copies an object if
   // necessary, the object might be promoted to an old space.  The caller must
   // ensure the precondition that the object is (a) a heap object and (b) in
   // the heap's from space.
-  static inline void ScavengeObject(HeapObject** p, HeapObject* object);
+  static inline void ScavengeObject(HeapObject** p, HeapObject* object,
+                                    bool force_promotion = false);
   static inline SlotCallbackResult CheckAndScavengeObject(Heap* heap,
-                                                          Address slot_address);
+                                                          Address slot_address,
+                                                          bool force_promotion);
 
   // Slow part of {ScavengeObject} above.
-  static void ScavengeObjectSlow(HeapObject** p, HeapObject* object);
+  static void ScavengeObjectSlow(HeapObject** p, HeapObject* object,
+                                 bool force_promotion);
 
   // Chooses an appropriate static visitor table depending on the current state
   // of the heap (i.e. incremental marking, logging and profiling).
   void SelectScavengingVisitorsTable();
 
   Isolate* isolate();
   Heap* heap() { return heap_; }
 
  private:
   Heap* heap_;
@@ skipping 22 matching lines @@
 class StaticScavengeVisitor
     : public StaticNewSpaceVisitor<StaticScavengeVisitor> {
  public:
   static inline void VisitPointer(Heap* heap, HeapObject* object, Object** p);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_SCAVENGER_H_