Implement Microtask Delivery Queue

src/promise.js

Index: src/promise.js
diff --git a/src/promise.js b/src/promise.js
index db7863f8098f686cab2fc4545eab1429165797fc..552ce3df30a6ae2cf0d7e2f78195a58334972cd1 100644
--- a/src/promise.js
+++ b/src/promise.js
@@ -173,37 +173,29 @@ function PromiseCatch(onReject) {
 }
 
 function PromiseEnqueue(value, tasks) {
-  promiseEvents.push(value, tasks);
+  RunMicrotasks.queue.push(function() {
+    for (var i = 0; i < tasks.length; i += 2) {
+      PromiseHandle(value, tasks[i], tasks[i + 1])
+    }
+  });
+
   %SetMicrotaskPending(true);
 }
 
-function PromiseMicrotaskRunner() {
-  var events = promiseEvents;
-  if (events.length > 0) {
-    promiseEvents = new InternalArray;
-    for (var i = 0; i < events.length; i += 2) {
-      var value = events[i];
-      var tasks = events[i + 1];
-      for (var j = 0; j < tasks.length; j += 2) {
-        var handler = tasks[j];
-        var deferred = tasks[j + 1];
-        try {
-          var result = handler(value);
-          if (result === deferred.promise)
-            throw MakeTypeError('promise_cyclic', [result]);
-          else if (IsPromise(result))
-            result.chain(deferred.resolve, deferred.reject);
-          else
-            deferred.resolve(result);
-        } catch(e) {
-          // TODO(rossberg): perhaps log uncaught exceptions below.
-          try { deferred.reject(e) } catch(e) {}
-        }
-      }
-    }
+function PromiseHandle(value, handler, deferred) {
+  try {
+    var result = handler(value);
+    if (result === deferred.promise)
+      throw MakeTypeError('promise_cyclic', [result]);
+    else if (IsPromise(result))
+      result.chain(deferred.resolve, deferred.reject);
+    else
+      deferred.resolve(result);
+  } catch(e) {
+    // TODO(rossberg): perhaps log uncaught exceptions below.
+    try { deferred.reject(e) } catch(e) {}
   }
 }
-RunMicrotasks.runners.push(PromiseMicrotaskRunner);
 
 
 // Multi-unwrapped chaining with thenable coercion.