Synchronize store buffer processing and concurrent sweeping.

src/heap-inl.h

Index: src/heap-inl.h
diff --git a/src/heap-inl.h b/src/heap-inl.h
index ea7dcda3b0acd8aee62f2507a5ab5852bd7196d1..cac969caedc5ac6bac24a21d4e68d457f8367c72 100644
--- a/src/heap-inl.h
+++ b/src/heap-inl.h
@@ -524,7 +524,9 @@ void Heap::UpdateAllocationSiteFeedback(HeapObject* object,
 }
 
 
-void Heap::ScavengeObject(HeapObject** p, HeapObject* object) {
+void Heap::ScavengeObject(HeapObject** p,
+                          HeapObject* object,
+                          Object* old_object) {
   ASSERT(object->GetIsolate()->heap()->InFromSpace(object));
 
   // We use the first word (where the map pointer usually is) of a heap