Promise.all and Promise.race use "then" rather than "chain".

src/promise.js

 // Copyright 2012 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 236 matching lines @@
 
 function PromiseAll(values) {
   var deferred = %_CallFunction(this, PromiseDeferred);
   var resolutions = [];
   try {
     var count = values.length;
     if (count === 0) {
       deferred.resolve(resolutions);
     } else {
       for (var i = 0; i < values.length; ++i) {
-        this.cast(values[i]).chain(
+        this.cast(values[i]).then(
           function(i, x) {
             resolutions[i] = x;
             if (--count === 0) deferred.resolve(resolutions);
           }.bind(UNDEFINED, i),  // TODO(rossberg): use let loop once available
           function(r) { deferred.reject(r) }
         );
       }
     }
   } catch (e) {
     deferred.reject(e)
   }
   return deferred.promise;
 }
 
 function PromiseOne(values) {
   var deferred = %_CallFunction(this, PromiseDeferred);
   try {
     for (var i = 0; i < values.length; ++i) {
-      this.cast(values[i]).chain(
+      this.cast(values[i]).then(
         function(x) { deferred.resolve(x) },
         function(r) { deferred.reject(r) }
       );
     }
   } catch (e) {
     deferred.reject(e)
   }
   return deferred.promise;
 }
 
@@ skipping 12 matching lines @@
     "cast", PromiseCast
   ]);
   InstallFunctions($Promise.prototype, DONT_ENUM, [
     "chain", PromiseChain,
     "then", PromiseThen,
     "catch", PromiseCatch
   ]);
 }
 
 SetUpPromise();