Use slot instead of value in the write barrier to record write from code.

src/incremental-marking.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 109 matching lines @@
   inline void RestartIfNotMarking() {
     if (state_ == COMPLETE) {
       state_ = MARKING;
       if (FLAG_trace_incremental_marking) {
         PrintF("[IncrementalMarking] Restarting (new grey objects)\n");
       }
     }
   }
 
   static void RecordWriteFromCode(HeapObject* obj,
-                                  Object* value,
+                                  Object** slot,
                                   Isolate* isolate);
 
   static void RecordWriteForEvacuationFromCode(HeapObject* obj,
                                                Object** slot,
                                                Isolate* isolate);
 
   // Record a slot for compaction.  Returns false for objects that are
   // guaranteed to be rescanned or not guaranteed to survive.
   //
   // No slots in white objects should be recorded, as some slots are typed and
@@ skipping 135 matching lines @@
   intptr_t write_barriers_invoked_since_last_step_;
 
   int no_marking_scope_depth_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(IncrementalMarking);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_INCREMENTAL_MARKING_H_