Use symbols instead of hidden properties for i18n markers.

src/heap-snapshot-generator.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/heap-snapshot-generator-inl.h"
 
 #include "src/allocation-tracker.h"
 #include "src/code-stubs.h"
@@ skipping 2146 matching lines @@
 #define NAME_ENTRY(name) strong_gc_subroot_names_.SetTag(heap_->name(), #name);
 #define ROOT_NAME(type, name, camel_name) NAME_ENTRY(name)
     STRONG_ROOT_LIST(ROOT_NAME)
 #undef ROOT_NAME
 #define STRUCT_MAP_NAME(NAME, Name, name) NAME_ENTRY(name##_map)
     STRUCT_LIST(STRUCT_MAP_NAME)
 #undef STRUCT_MAP_NAME
 #define STRING_NAME(name, str) NAME_ENTRY(name)
     INTERNALIZED_STRING_LIST(STRING_NAME)
 #undef STRING_NAME
+#define SYMBOL_NAME(name) NAME_ENTRY(name)
+    PRIVATE_SYMBOL_LIST(SYMBOL_NAME)
+#undef SYMBOL_NAME
 #undef NAME_ENTRY
     CHECK(!strong_gc_subroot_names_.is_empty());
   }
   return strong_gc_subroot_names_.GetTag(object);
 }
 
 
 void V8HeapExplorer::TagObject(Object* obj, const char* tag) {
   if (IsEssentialObject(obj)) {
     HeapEntry* entry = GetEntry(obj);
@@ skipping 960 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