[promises] Remove deferred object

src/js/async-await.js

 // Copyright 2016 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();
 
 // -------------------------------------------------------------------
 // Imports
 
 var AsyncFunctionNext;
 var AsyncFunctionThrow;
-var CreateInternalPromiseCapability;
 var PromiseCreate;
 var PromiseNextMicrotaskID;
 var RejectPromise;
 
 utils.Import(function(from) {
   AsyncFunctionNext = from.AsyncFunctionNext;
   AsyncFunctionThrow = from.AsyncFunctionThrow;
-  CreateInternalPromiseCapability = from.CreateInternalPromiseCapability;
   PromiseCreate = from.PromiseCreate;
   RejectPromise = from.RejectPromise;
 });
 
 var promiseAsyncStackIDSymbol =
     utils.ImportNow("promise_async_stack_id_symbol");
 var promiseHandledBySymbol =
     utils.ImportNow("promise_handled_by_symbol");
 var promiseForwardingHandlerSymbol =
     utils.ImportNow("promise_forwarding_handler_symbol");
 
 // -------------------------------------------------------------------
 
 function PromiseCastResolved(value) {
   // TODO(caitp): This is non spec compliant. See v8:5694.
   if (%is_promise(value)) {
     return value;
   } else {
-    var promise = PromiseCreate();
+    var promise = PromiseCreate(UNDEFINED);
     %promise_resolve(promise, value);
     return promise;
   }
 }
 
 // ES#abstract-ops-async-function-await
 // AsyncFunctionAwait ( value )
 // Shared logic for the core of await. The parser desugars
 //   await awaited
 // into
@@ skipping 18 matching lines @@
   };
   var onRejected = sentError => {
     %_Call(AsyncFunctionThrow, generator, sentError);
     // Similarly, returning the huge Promise here would cause a long
     // resolution chain to find what the exception to throw is, and
     // create a similar memory leak, and it does not matter what
     // sort of rejection this intermediate Promise becomes.
     return;
   }
 
-  // Just forwarding the exception, so no debugEvent for throwawayCapability.
-  var throwawayCapability = CreateInternalPromiseCapability(promise);
+  var throwawayPromise = PromiseCreate(promise);
 
   // The Promise will be thrown away and not handled, but it shouldn't trigger
   // unhandled reject events as its work is done
-  %PromiseMarkAsHandled(throwawayCapability.promise);
+  %PromiseMarkAsHandled(throwawayPromise);
 
   if (DEBUG_IS_ACTIVE) {
     if (%is_promise(awaited)) {
       // Mark the reject handler callback to be a forwarding edge, rather
       // than a meaningful catch handler
       SET_PRIVATE(onRejected, promiseForwardingHandlerSymbol, true);
     }
 
     // Mark the dependency to outerPromise in case the throwaway Promise is
     // found on the Promise stack
-    SET_PRIVATE(throwawayCapability.promise, promiseHandledBySymbol,
-                outerPromise);
+    SET_PRIVATE(throwawayPromise, promiseHandledBySymbol, outerPromise);
   }
 
-  %perform_promise_then(promise, onFulfilled, onRejected, throwawayCapability);
+  %perform_promise_then(promise, onFulfilled, onRejected, throwawayPromise);
 }
 
 // Called by the parser from the desugaring of 'await' when catch
 // prediction indicates no locally surrounding catch block
 function AsyncFunctionAwaitUncaught(generator, awaited, outerPromise) {
   AsyncFunctionAwait(generator, awaited, outerPromise);
 }
 
 // Called by the parser from the desugaring of 'await' when catch
 // prediction indicates that there is a locally surrounding catch block
@@ skipping 43 matching lines @@
 
 %InstallToContext([
   "async_function_await_caught", AsyncFunctionAwaitCaught,
   "async_function_await_uncaught", AsyncFunctionAwaitUncaught,
   "reject_promise_no_debug_event", RejectPromiseNoDebugEvent,
   "async_function_promise_create", AsyncFunctionPromiseCreate,
   "async_function_promise_release", AsyncFunctionPromiseRelease,
 ]);
 
 })