[promises] Move PromiseResolveThenableJob to c++

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 266 matching lines @@
           %PromiseRevokeReject(resolution);
         }
         // Don't cause a debug event as this case is forwarding a rejection
         RejectPromise(promise, thenableValue, false);
         SET_PRIVATE(resolution, promiseHasHandlerSymbol, true);
         return;
       }
     }
 
     if (IS_CALLABLE(then)) {
-      // PromiseResolveThenableJob
-      var id;
-      var name = "PromiseResolveThenableJob";
+      var callbacks = CreateResolvingFunctions(promise, false);
+      var id, before_debug_event, after_debug_event;
       var instrumenting = DEBUG_IS_ACTIVE;
-      if (instrumenting && IsPromise(resolution)) {
-        // Mark the dependency of the new promise on the resolution
-        SET_PRIVATE(resolution, promiseHandledBySymbol, promise);
+      if (instrumenting) {
+        if (IsPromise(resolution)) {
+          // Mark the dependency of the new promise on the resolution
+          SET_PRIVATE(resolution, promiseHandledBySymbol, promise);
+        }
+        id = ++lastMicrotaskId;
+        before_debug_event = {
+          type: "willHandle",
+          id: id,
+          name: "PromiseResolveThenableJob"
+        };
+        after_debug_event = {
+          type: "didHandle",
+          id: id,
+          name: "PromiseResolveThenableJob"
+        };
+        %DebugAsyncTaskEvent({
+          type: "enqueue",
+          id: id,
+          name: "PromiseResolveThenableJob"
+        });
       }
-      %EnqueueMicrotask(function() {
-        if (instrumenting) {
-          %DebugAsyncTaskEvent({ type: "willHandle", id: id, name: name });
-        }
-        // These resolving functions simply forward the exception, so
-        // don't create a new debugEvent.
-        var callbacks = CreateResolvingFunctions(promise, false);
-        try {
-          %_Call(then, resolution, callbacks.resolve, callbacks.reject);
-        } catch (e) {
-          %_Call(callbacks.reject, UNDEFINED, e);
-        }
-        if (instrumenting) {
-          %DebugAsyncTaskEvent({ type: "didHandle", id: id, name: name });
-        }
-      });
-      if (instrumenting) {
-        id = ++lastMicrotaskId;
-        %DebugAsyncTaskEvent({ type: "enqueue", id: id, name: name });
-      }
+      %EnqueuePromiseResolveThenableJob(
+          resolution, then, callbacks.resolve, callbacks.reject,
+          before_debug_event, after_debug_event);
       return;
     }
   }
   FulfillPromise(promise, kFulfilled, resolution,
                  promiseFulfillReactionsSymbol);
 }
 
 // ES#sec-rejectpromise
 // RejectPromise ( promise, reason )
 function RejectPromise(promise, reason, debugEvent) {
@@ skipping 323 matching lines @@
   "then", PromiseThen,
   "catch", PromiseCatch
 ]);
 
 %InstallToContext([
   "promise_catch", PromiseCatch,
   "promise_create", PromiseCreate,
   "promise_has_user_defined_reject_handler", PromiseHasUserDefinedRejectHandler,
   "promise_reject", DoRejectPromise,
   "promise_resolve", ResolvePromise,
-  "promise_then", PromiseThen,
+  "promise_then", PromiseThen
 ]);
 
 // 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", DoRejectPromise
 ]);
 
 utils.Export(function(to) {
   to.IsPromise = IsPromise;
   to.PromiseCreate = PromiseCreate;
   to.PromiseThen = PromiseThen;
 
   to.GlobalPromise = GlobalPromise;
   to.NewPromiseCapability = NewPromiseCapability;
   to.PerformPromiseThen = PerformPromiseThen;
   to.ResolvePromise = ResolvePromise;
   to.RejectPromise = RejectPromise;
 });
 
 })