API support for promises

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 84 matching lines @@
 
 function PromiseResolve(promise, x) {
   PromiseDone(promise, +1, x, promiseOnResolve)
 }
 
 function PromiseReject(promise, r) {
   PromiseDone(promise, -1, r, promiseOnReject)
 }
 
 
+// For API.
+
+function PromiseNopResolver() {}
+
+function PromiseCreate() {
+  return new Promise(PromiseNopResolver)
+}
+
+
 // Convenience.
 
 function PromiseDeferred() {
   if (this === $Promise) {
     // Optimized case, avoid extra closure.
     var promise = PromiseInit(new Promise(promiseRaw));
     return {
       promise: promise,
       resolve: function(x) { PromiseResolve(promise, x) },
       reject: function(r) { PromiseReject(promise, r) }
@@ skipping 192 matching lines @@
     "cast", PromiseCast
   ]);
   InstallFunctions($Promise.prototype, DONT_ENUM, [
     "chain", PromiseChain,
     "then", PromiseThen,
     "catch", PromiseCatch
   ]);
 }
 
 SetUpPromise();