Add Box object to heap profiler.

src/heap-snapshot-generator.cc

 // Copyright 2013 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 1029 matching lines @@
   } else if (obj->IsSharedFunctionInfo()) {
     ExtractSharedFunctionInfoReferences(entry, SharedFunctionInfo::cast(obj));
   } else if (obj->IsScript()) {
     ExtractScriptReferences(entry, Script::cast(obj));
   } else if (obj->IsAccessorPair()) {
     ExtractAccessorPairReferences(entry, AccessorPair::cast(obj));
   } else if (obj->IsCodeCache()) {
     ExtractCodeCacheReferences(entry, CodeCache::cast(obj));
   } else if (obj->IsCode()) {
     ExtractCodeReferences(entry, Code::cast(obj));
+  } else if (obj->IsBox()) {
+    ExtractBoxReferences(entry, Box::cast(obj));
   } else if (obj->IsCell()) {
     ExtractCellReferences(entry, Cell::cast(obj));
   } else if (obj->IsPropertyCell()) {
     ExtractPropertyCellReferences(entry, PropertyCell::cast(obj));
   } else if (obj->IsAllocationSite()) {
     ExtractAllocationSiteReferences(entry, AllocationSite::cast(obj));
   }
   SetInternalReference(obj, entry, "map", obj->map(), HeapObject::kMapOffset);
 
   // Extract unvisited fields as hidden references and restore tags
@@ skipping 350 matching lines @@
                        "constant_pool", code->constant_pool(),
                        Code::kConstantPoolOffset);
   if (code->kind() == Code::OPTIMIZED_FUNCTION) {
     SetWeakReference(code, entry,
                      "next_code_link", code->next_code_link(),
                      Code::kNextCodeLinkOffset);
   }
 }
 
 
+void V8HeapExplorer::ExtractBoxReferences(int entry, Box* box) {
+  SetInternalReference(box, entry, "value", box->value(), Box::kValueOffset);
+}
+
+
 void V8HeapExplorer::ExtractCellReferences(int entry, Cell* cell) {
   SetInternalReference(cell, entry, "value", cell->value(), Cell::kValueOffset);
 }
 
 
 void V8HeapExplorer::ExtractPropertyCellReferences(int entry,
                                                    PropertyCell* cell) {
   ExtractCellReferences(entry, cell);
   SetInternalReference(cell, entry, "type", cell->type(),
                        PropertyCell::kTypeOffset);
@@ skipping 1563 matching lines @@
   writer_->AddString("\"<dummy>\"");
   for (int i = 1; i < sorted_strings.length(); ++i) {
     writer_->AddCharacter(',');
     SerializeString(sorted_strings[i]);
     if (writer_->aborted()) return;
   }
 }
 
 
 } }  // namespace v8::internal