Synchronize store buffer processing and concurrent sweeping.

src/store-buffer.h

 // Copyright 2011 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 23 matching lines @@
 #include "platform.h"
 #include "v8globals.h"
 
 namespace v8 {
 namespace internal {
 
 class Page;
 class PagedSpace;
 class StoreBuffer;
 
-typedef void (*ObjectSlotCallback)(HeapObject** from, HeapObject* to);
+typedef void (*ObjectSlotCallback)(HeapObject** address,
+                                   HeapObject* new_value,
+                                   Object* old_value);
 
 typedef void (StoreBuffer::*RegionCallback)(Address start,
                                             Address end,
                                             ObjectSlotCallback slot_callback,
                                             bool clear_maps);
 
 // Used to implement the write barrier by collecting addresses of pointers
 // between spaces.
 class StoreBuffer {
  public:
@@ skipping 206 matching lines @@
   }
 
  private:
   StoreBuffer* store_buffer_;
   bool stored_state_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_STORE_BUFFER_H_