Introduce debug events for promises.

src/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.
 
 "use strict";
 
 // This file relies on the fact that the following declaration has been made
 // in runtime.js:
 // var $Object = global.Object
 // var $WeakMap = global.WeakMap
@@ skipping 20 matching lines @@
 var promiseRaw = GLOBAL_PRIVATE("Promise#raw");
 
 (function() {
 
   var $Promise = function Promise(resolver) {
     if (resolver === promiseRaw) return;
     if (!%_IsConstructCall()) throw MakeTypeError('not_a_promise', [this]);
     if (!IS_SPEC_FUNCTION(resolver))
       throw MakeTypeError('resolver_not_a_function', [resolver]);
     var promise = PromiseInit(this);
+    if (DEBUG_IS_ACTIVE) {
+      %DebugPromiseEvent({ type : "new Promise",
+                           promise: this,
+                           resolver: resolver });
+    }
     try {
       %DebugPromiseHandlePrologue(function() { return promise });
       resolver(function(x) { PromiseResolve(promise, x) },
                function(r) { PromiseReject(promise, r) });
     } catch (e) {
       PromiseReject(promise, e);
     } finally {
       %DebugPromiseHandleEpilogue();
     }
   }
@@ skipping 257 matching lines @@
     "race", PromiseOne,
     "resolve", PromiseCast
   ]);
   InstallFunctions($Promise.prototype, DONT_ENUM, [
     "chain", PromiseChain,
     "then", PromiseThen,
     "catch", PromiseCatch
   ]);
 
 })();