AllocationSite objects weakly linked for traversal

src/serialize.h

Index: src/serialize.h
diff --git a/src/serialize.h b/src/serialize.h
index a6099afc23f397fdcfedea0781cca8c7767c5ec2..86ccf6e4f34b1cb658cbb4c720d82fc796df02dd 100644
--- a/src/serialize.h
+++ b/src/serialize.h
@@ -339,6 +339,8 @@ class Deserializer: public SerializerDeserializer {
  private:
   virtual void VisitPointers(Object** start, Object** end);
 
+  virtual void VisitAllocationSite(HeapObject* site);
+
   virtual void VisitExternalReferences(Address* start, Address* end) {
     UNREACHABLE();
   }
@@ -487,6 +489,8 @@ class Serializer : public SerializerDeserializer {
                WhereToPoint where,
                int skip);
 
+  Isolate* isolate() { return isolate_; }
+
  protected:
   static const int kInvalidRootIndex = -1;
 
@@ -518,6 +522,7 @@ class Serializer : public SerializerDeserializer {
     void VisitExternalReferences(Address* start, Address* end);
     void VisitExternalReference(RelocInfo* rinfo);
     void VisitCodeTarget(RelocInfo* target);
+    void VisitAllocationSite(HeapObject* site);
     void VisitCodeEntry(Address entry_address);
     void VisitCell(RelocInfo* rinfo);
     void VisitRuntimeEntry(RelocInfo* reloc);