Use body descriptor to update pointers from cells.

src/mark-compact.cc

Index: src/mark-compact.cc
diff --git a/src/mark-compact.cc b/src/mark-compact.cc
index c06bfd7f7323825d4c0f278c04e39260eaf3cc4f..05a196e4c13d86aed2b505d3efd812ce9c40417d 100644
--- a/src/mark-compact.cc
+++ b/src/mark-compact.cc
@@ -3418,26 +3418,16 @@ void MarkCompactCollector::EvacuateNewSpaceAndCandidates() {
        cell != NULL;
        cell = cell_iterator.Next()) {
     if (cell->IsCell()) {
-      Address value_address = reinterpret_cast<Address>(cell) +
-          (Cell::kValueOffset - kHeapObjectTag);
-      updating_visitor.VisitPointer(reinterpret_cast<Object**>(value_address));
+      Cell::BodyDescriptor::IterateBody(cell, &updating_visitor);
     }
   }
 
-  HeapObjectIterator js_global_property_cell_iterator(
-      heap_->property_cell_space());
-  for (HeapObject* cell = js_global_property_cell_iterator.Next();
+  HeapObjectIterator property_cell_iterator(heap_->property_cell_space());
+  for (HeapObject* cell = property_cell_iterator.Next();
        cell != NULL;
-       cell = js_global_property_cell_iterator.Next()) {
+       cell = property_cell_iterator.Next()) {
     if (cell->IsPropertyCell()) {
-      Address value_address =
-          reinterpret_cast<Address>(cell) +
-          (PropertyCell::kValueOffset - kHeapObjectTag);
-      updating_visitor.VisitPointer(reinterpret_cast<Object**>(value_address));
-      Address type_address =
-          reinterpret_cast<Address>(cell) +
-          (PropertyCell::kTypeOffset - kHeapObjectTag);
-      updating_visitor.VisitPointer(reinterpret_cast<Object**>(type_address));
+      PropertyCell::BodyDescriptor::IterateBody(cell, &updating_visitor);
     }
   }