Bugfix: AllocationSite objects need to be walkable by the heap snapshot

src/heap-snapshot-generator.cc

Index: src/heap-snapshot-generator.cc
diff --git a/src/heap-snapshot-generator.cc b/src/heap-snapshot-generator.cc
index d65b8140039e43eb1e7c9d76747c54e6c3d0c1da..cb1fa4d58d2ec18148c15736a42abb853a72dc7b 100644
--- a/src/heap-snapshot-generator.cc
+++ b/src/heap-snapshot-generator.cc
@@ -955,9 +955,10 @@ void V8HeapExplorer::ExtractReferences(HeapObject* obj) {
     ExtractCellReferences(entry, Cell::cast(obj));
     extract_indexed_refs = false;
   } else if (obj->IsPropertyCell()) {
-    ExtractPropertyCellReferences(
-        entry, PropertyCell::cast(obj));
+    ExtractPropertyCellReferences(entry, PropertyCell::cast(obj));
     extract_indexed_refs = false;
+  } else if (obj->IsAllocationSite()) {
+    ExtractAllocationSiteReferences(entry, AllocationSite::cast(obj));
   }
   if (extract_indexed_refs) {
     SetInternalReference(obj, entry, "map", obj->map(), HeapObject::kMapOffset);
@@ -1264,6 +1265,13 @@ void V8HeapExplorer::ExtractPropertyCellReferences(int entry,
 }
 
 
+void V8HeapExplorer::ExtractAllocationSiteReferences(int entry,
+                                                     AllocationSite* site) {
+  SetInternalReference(site, entry, "transition_info", site->transition_info(),
+                       AllocationSite::kTransitionInfoOffset);
+}
+
+
 void V8HeapExplorer::ExtractClosureReferences(JSObject* js_obj, int entry) {
   if (!js_obj->IsJSFunction()) return;