Speed up clearing of old to new slots in dead objects.

src/heap/remembered-set.h

 // Copyright 2016 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_REMEMBERED_SET_H
 #define V8_REMEMBERED_SET_H
 
 #include "src/heap/heap.h"
 #include "src/heap/slot-set.h"
 #include "src/heap/spaces.h"
@@ skipping 218 matching lines @@
       // just freed free space object.
       if (heap->InToSpace(object)) {
         return KEEP_SLOT;
       }
     } else {
       DCHECK(!heap->InNewSpace(object));
     }
     return REMOVE_SLOT;
   }
 
-  static bool IsValidSlot(Heap* heap, Object** slot);
+  static bool IsValidSlot(Heap* heap, MemoryChunk* chunk, Object** slot);
 };
 
 // Buffer for keeping thead local migration slots during compaction.
 // TODO(ulan): Remove this once every thread gets local pages in compaction
 // space.
 class LocalSlotsBuffer BASE_EMBEDDED {
  public:
   LocalSlotsBuffer() : top_(new Node(nullptr)) {}
 
   ~LocalSlotsBuffer() {
@@ skipping 66 matching lines @@
     int count;
   };
 
   Node* top_;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_REMEMBERED_SET_H