Native context: do not put public symbols and flags on the js builtins object.

src/collection-iterator.js

 // Copyright 2014 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.
 
 var $mapEntries;
 var $mapIteratorNext;
 var $setIteratorNext;
 var $setValues;
 
 (function(global, utils) {
 
 "use strict";
 
 %CheckIsBootstrapping();
 
 var GlobalMap = global.Map;
 var GlobalSet = global.Set;
+var iteratorSymbol = utils.ImportNow("iterator_symbol");
+var toStringTagSymbol = utils.ImportNow("to_string_tag_symbol");
 
 // -------------------------------------------------------------------
 
 function SetIteratorConstructor(set, kind) {
   %SetIteratorInitialize(this, set, kind);
 }
 
 
 function SetIteratorNextJS() {
   if (!IS_SET_ITERATOR(this)) {
@@ skipping 39 matching lines @@
 
 // -------------------------------------------------------------------
 
 %SetCode(SetIterator, SetIteratorConstructor);
 %FunctionSetPrototype(SetIterator, {__proto__: $iteratorPrototype});
 %FunctionSetInstanceClassName(SetIterator, 'Set Iterator');
 utils.InstallFunctions(SetIterator.prototype, DONT_ENUM, [
   'next', SetIteratorNextJS
 ]);
 
-%AddNamedProperty(SetIterator.prototype, symbolToStringTag,
+%AddNamedProperty(SetIterator.prototype, toStringTagSymbol,
     "Set Iterator", READ_ONLY | DONT_ENUM);
 
 utils.InstallFunctions(GlobalSet.prototype, DONT_ENUM, [
   'entries', SetEntries,
   'keys', SetValues,
   'values', SetValues
 ]);
 
-%AddNamedProperty(GlobalSet.prototype, symbolIterator, SetValues, DONT_ENUM);
+%AddNamedProperty(GlobalSet.prototype, iteratorSymbol, SetValues, DONT_ENUM);
 
 $setIteratorNext = SetIteratorNextJS;
 $setValues = SetValues;
 
 // -------------------------------------------------------------------
 
 function MapIteratorConstructor(map, kind) {
   %MapIteratorInitialize(this, map, kind);
 }
 
@@ skipping 52 matching lines @@
 
 // -------------------------------------------------------------------
 
 %SetCode(MapIterator, MapIteratorConstructor);
 %FunctionSetPrototype(MapIterator, {__proto__: $iteratorPrototype});
 %FunctionSetInstanceClassName(MapIterator, 'Map Iterator');
 utils.InstallFunctions(MapIterator.prototype, DONT_ENUM, [
   'next', MapIteratorNextJS
 ]);
 
-%AddNamedProperty(MapIterator.prototype, symbolToStringTag,
+%AddNamedProperty(MapIterator.prototype, toStringTagSymbol,
     "Map Iterator", READ_ONLY | DONT_ENUM);
 
 
 utils.InstallFunctions(GlobalMap.prototype, DONT_ENUM, [
   'entries', MapEntries,
   'keys', MapKeys,
   'values', MapValues
 ]);
 
-%AddNamedProperty(GlobalMap.prototype, symbolIterator, MapEntries, DONT_ENUM);
+%AddNamedProperty(GlobalMap.prototype, iteratorSymbol, MapEntries, DONT_ENUM);
 
 $mapEntries = MapEntries;
 $mapIteratorNext = MapIteratorNextJS;
 
 })