Install iterator meta objects via utils object.

src/js/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.
 
 (function(global, utils) {
 
 "use strict";
 
 %CheckIsBootstrapping();
 
 var GlobalMap = global.Map;
 var GlobalSet = global.Set;
 var iteratorSymbol = utils.ImportNow("iterator_symbol");
+var MapIterator = utils.ImportNow("MapIterator");
 var toStringTagSymbol = utils.ImportNow("to_string_tag_symbol");
+var SetIterator = utils.ImportNow("SetIterator");
 
 // -------------------------------------------------------------------
 
 function SetIteratorConstructor(set, kind) {
   %SetIteratorInitialize(this, set, kind);
 }
 
 
 function SetIteratorNextJS() {
   if (!IS_SET_ITERATOR(this)) {
@@ skipping 33 matching lines @@
   if (!IS_SET(this)) {
     throw MakeTypeError(kIncompatibleMethodReceiver,
                         'Set.prototype.values', this);
   }
   return new SetIterator(this, ITERATOR_KIND_VALUES);
 }
 
 // -------------------------------------------------------------------
 
 %SetCode(SetIterator, SetIteratorConstructor);
-%FunctionSetPrototype(SetIterator, {__proto__: $iteratorPrototype});
 %FunctionSetInstanceClassName(SetIterator, 'Set Iterator');
 utils.InstallFunctions(SetIterator.prototype, DONT_ENUM, [
   'next', SetIteratorNextJS
 ]);
 
 %AddNamedProperty(SetIterator.prototype, toStringTagSymbol,
     "Set Iterator", READ_ONLY | DONT_ENUM);
 
 utils.InstallFunctions(GlobalSet.prototype, DONT_ENUM, [
   'entries', SetEntries,
@@ skipping 58 matching lines @@
   if (!IS_MAP(this)) {
     throw MakeTypeError(kIncompatibleMethodReceiver,
                         'Map.prototype.values', this);
   }
   return new MapIterator(this, ITERATOR_KIND_VALUES);
 }
 
 // -------------------------------------------------------------------
 
 %SetCode(MapIterator, MapIteratorConstructor);
-%FunctionSetPrototype(MapIterator, {__proto__: $iteratorPrototype});
 %FunctionSetInstanceClassName(MapIterator, 'Map Iterator');
 utils.InstallFunctions(MapIterator.prototype, DONT_ENUM, [
   'next', MapIteratorNextJS
 ]);
 
 %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, iteratorSymbol, MapEntries, DONT_ENUM);
 
 // -------------------------------------------------------------------
 // Exports
 
 utils.Export(function(to) {
   to.MapEntries = MapEntries;
   to.MapIteratorNext = MapIteratorNextJS;
   to.SetIteratorNext = SetIteratorNextJS;
   to.SetValues = SetValues;
 });
 
 })