Make Promise.all/Promise.race catch prediction conditional on DevTools

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 462 matching lines @@
   }
 
   // false debugEvent so that forwarding the rejection through all does not
   // trigger redundant ExceptionEvents
   var deferred = NewPromiseCapability(this, false);
   var resolutions = new InternalArray();
   var count;
 
   // For catch prediction, don't treat the .then calls as handling it;
   // instead, recurse outwards.
-  SET_PRIVATE(deferred.reject, promiseForwardingHandlerSymbol, true);
+  var instrumenting = DEBUG_IS_ACTIVE;
+  if (instrumenting) {
+    SET_PRIVATE(deferred.reject, promiseForwardingHandlerSymbol, true);
+  }
 
   function CreateResolveElementFunction(index, values, promiseCapability) {
     var alreadyCalled = false;
     return (x) => {
       if (alreadyCalled === true) return;
       alreadyCalled = true;
       values[index] = x;
       if (--count === 0) {
         var valuesArray = [];
         %MoveArrayContents(values, valuesArray);
         %_Call(promiseCapability.resolve, UNDEFINED, valuesArray);
       }
     };
   }
 
   try {
     var i = 0;
     count = 1;
     for (var value of iterable) {
       var nextPromise = this.resolve(value);
       ++count;
       var throwawayPromise = nextPromise.then(
           CreateResolveElementFunction(i, resolutions, deferred),
           deferred.reject);
       // For catch prediction, mark that rejections here are semantically
       // handled by the combined Promise.
-      if (IsPromise(throwawayPromise)) {
+      if (instrumenting && IsPromise(throwawayPromise)) {
         SET_PRIVATE(throwawayPromise, promiseHandledBySymbol, deferred.promise);
       }
       ++i;
     }
 
     // 6.d
     if (--count === 0) {
       var valuesArray = [];
       %MoveArrayContents(resolutions, valuesArray);
       %_Call(deferred.resolve, UNDEFINED, valuesArray);
@@ skipping 11 matching lines @@
   if (!IS_RECEIVER(this)) {
     throw %make_type_error(kCalledOnNonObject, PromiseRace);
   }
 
   // false debugEvent so that forwarding the rejection through race does not
   // trigger redundant ExceptionEvents
   var deferred = NewPromiseCapability(this, false);
 
   // For catch prediction, don't treat the .then calls as handling it;
   // instead, recurse outwards.
-  SET_PRIVATE(deferred.reject, promiseForwardingHandlerSymbol, true);
+  var instrumenting = DEBUG_IS_ACTIVE;
+  if (instrumenting) {
+    SET_PRIVATE(deferred.reject, promiseForwardingHandlerSymbol, true);
+  }
 
   try {
     for (var value of iterable) {
       var throwawayPromise = this.resolve(value).then(deferred.resolve,
                                                       deferred.reject);
       // For catch prediction, mark that rejections here are semantically
       // handled by the combined Promise.
-      if (IsPromise(throwawayPromise)) {
+      if (instrumenting && IsPromise(throwawayPromise)) {
         SET_PRIVATE(throwawayPromise, promiseHandledBySymbol, deferred.promise);
       }
     }
   } catch (e) {
     deferred.reject(e)
   }
   return deferred.promise;
 }
 
 
@@ skipping 106 matching lines @@
   to.PromiseThen = PromiseThen;
 
   to.GlobalPromise = GlobalPromise;
   to.NewPromiseCapability = NewPromiseCapability;
   to.PerformPromiseThen = PerformPromiseThen;
   to.ResolvePromise = ResolvePromise;
   to.RejectPromise = RejectPromise;
 });
 
 })