Harden internal uses of .chain

test/mjsunit/es6/promises.js

 // 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 772 matching lines @@
   log = ""
   var d6 = MyPromise.defer()
   d6.promise.chain(function(x) {
     return new Promise(function(resolve) { resolve(x) })
   }).chain(function() {})
   d6.resolve(6)
   assertTrue(log === "dncncnx6", "subclass/chain")
 
   log = ""
   Promise.all([11, Promise.accept(12), 13, MyPromise.accept(14), 15, 16])
-  assertTrue(log === "nx14cn", "subclass/all/arg")
+  assertTrue(log === "nx14n", "subclass/all/arg")
 
   log = ""
   MyPromise.all([21, Promise.accept(22), 23, MyPromise.accept(24), 25, 26])
-  assertTrue(log === "nx24nnx21cnnx23cncnnx25cnnx26cn", "subclass/all/self")
+  assertTrue(log === "nx24nnx21nnx23nnnx25nnx26n", "subclass/all/self")
 })();
 
 
 assertAsyncDone()