Introduce more 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 22 matching lines @@
 
 (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",
+      %DebugPromiseEvent({ type : "new",
                            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();
     }
   }
 
   // Core functionality.
 
   function PromiseSet(promise, status, value, onResolve, onReject) {
     SET_PRIVATE(promise, promiseStatus, status);
     SET_PRIVATE(promise, promiseValue, value);
     SET_PRIVATE(promise, promiseOnResolve, onResolve);
     SET_PRIVATE(promise, promiseOnReject, onReject);
+    if (DEBUG_IS_ACTIVE && status !== 0) {
+      %DebugPromiseEvent({ type: "update",
+                           promise: promise,
+                           status: status,
+                           value: value });
+    }
     return promise;
   }
 
   function PromiseInit(promise) {
     return PromiseSet(
         promise, 0, UNDEFINED, new InternalArray, new InternalArray)
   }
 
   function PromiseDone(promise, status, value, promiseQueue) {
     if (GET_PRIVATE(promise, promiseStatus) === 0) {
@@ skipping 152 matching lines @@
         PromiseEnqueue(GET_PRIVATE(this, promiseValue),
                        [onResolve, deferred],
                        +1);
         break;
       case -1:  // Rejected
         PromiseEnqueue(GET_PRIVATE(this, promiseValue),
                        [onReject, deferred],
                        -1);
         break;
     }
+    if (DEBUG_IS_ACTIVE) {
+      %DebugPromiseEvent({ type: "chain",
+                           promise: deferred.promise,
+                           parentPromise: this });
+    }
     return deferred.promise;
   }
 
   PromiseCatch = function PromiseCatch(onReject) {
     return this.then(UNDEFINED, onReject);
   }
 
   // Multi-unwrapped chaining with thenable coercion.
 
   PromiseThen = function PromiseThen(onResolve, onReject) {
@@ skipping 87 matching lines @@
     "race", PromiseOne,
     "resolve", PromiseCast
   ]);
   InstallFunctions($Promise.prototype, DONT_ENUM, [
     "chain", PromiseChain,
     "then", PromiseThen,
     "catch", PromiseCatch
   ]);
 
 })();