Remove --promise-extra flag

src/js/promise.js

 // Copyright 2012 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, extrasUtils) {
 
 "use strict";
 
 %CheckIsBootstrapping();
 
@@ skipping 328 matching lines @@
     result.resolve = resolve;
     result.reject = reject;
   });
 
   if (!IS_CALLABLE(result.resolve) || !IS_CALLABLE(result.reject))
       throw %make_type_error(kPromiseNonCallable);
 
   return result;
 }
 
-// Unspecified V8-specific legacy function
-function PromiseDefer() {
-  %IncrementUseCounter(kPromiseDefer);
-  return NewPromiseCapability(this);
-}
-
-// Unspecified V8-specific legacy function
-function PromiseAccept(x) {
-  %IncrementUseCounter(kPromiseAccept);
-  return %_Call(PromiseResolve, this, x);
-}
-
 // ES#sec-promise.reject
 // Promise.reject ( x )
 function PromiseReject(r) {
   if (!IS_RECEIVER(this)) {
     throw %make_type_error(kCalledOnNonObject, PromiseResolve);
   }
   if (this === GlobalPromise) {
     // Optimized case, avoid extra closure.
     var promise = PromiseCreateAndSet(kRejected, r);
     // The debug event for this would always be an uncaught promise reject,
@@ skipping 65 matching lines @@
   var status = GET_PRIVATE(this, promiseStateSymbol);
   if (IS_UNDEFINED(status)) {
     throw %make_type_error(kNotAPromise, this);
   }
 
   var constructor = SpeciesConstructor(this, GlobalPromise);
   var resultCapability = NewPromiseCapability(constructor);
   return PerformPromiseThen(this, onResolve, onReject, resultCapability);
 }
 
-// Unspecified V8-specific legacy function
-// Chain is left around for now as an alias for then
-function PromiseChain(onResolve, onReject) {
-  %IncrementUseCounter(kPromiseChain);
-  return %_Call(PromiseThen, this, onResolve, onReject);
-}
-
 // ES#sec-promise.prototype.catch
 // Promise.prototype.catch ( onRejected )
 function PromiseCatch(onReject) {
   return this.then(UNDEFINED, onReject);
 }
 
 // Combinators.
 
 // ES#sec-promise.resolve
 // Promise.resolve ( x )
@@ skipping 145 matching lines @@
 
 utils.InstallGetter(GlobalPromise, speciesSymbol, PromiseSpecies);
 
 utils.InstallFunctions(GlobalPromise.prototype, DONT_ENUM, [
   "then", PromiseThen,
   "catch", PromiseCatch
 ]);
 
 %InstallToContext([
   "promise_catch", PromiseCatch,
-  "promise_chain", PromiseChain,
   "promise_create", PromiseCreate,
   "promise_has_user_defined_reject_handler", PromiseHasUserDefinedRejectHandler,
   "promise_reject", RejectPromise,
   "promise_resolve", ResolvePromise,
   "promise_then", PromiseThen,
   "promise_create_rejected", PromiseCreateRejected,
   "promise_create_resolved", PromiseCreateResolved
 ]);
 
 // This allows extras to create promises quickly without building extra
 // resolve/reject closures, and allows them to later resolve and reject any
 // promise without having to hold on to those closures forever.
 utils.InstallFunctions(extrasUtils, 0, [
   "createPromise", PromiseCreate,
   "resolvePromise", ResolvePromise,
   "rejectPromise", RejectPromise
 ]);
 
-// TODO(v8:4567): Allow experimental natives to remove function prototype
-[PromiseChain, PromiseDefer, PromiseAccept].forEach(
-    fn => %FunctionRemovePrototype(fn));
-
 utils.Export(function(to) {
-  to.PromiseChain = PromiseChain;
-  to.PromiseDefer = PromiseDefer;
-  to.PromiseAccept = PromiseAccept;
-
   to.PromiseCastResolved = PromiseCastResolved;
   to.PromiseThen = PromiseThen;
 
   to.GlobalPromise = GlobalPromise;
   to.NewPromiseCapability = NewPromiseCapability;
   to.PerformPromiseThen = PerformPromiseThen;
 });
 
 })