Move microtask queueing logic from JavaScript to C++

src/object-observe.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";
 
 // Overview:
 //
 // This file contains all of the routing and accounting for Object.observe.
 // User code will interact with these mechanisms via the Object.observe APIs
@@ skipping 401 matching lines @@
   }
 
   var callback = ObserverGetCallback(observer);
   if (!%ObserverObjectAndRecordHaveSameOrigin(callback, changeRecord.object,
                                               changeRecord)) {
     return;
   }
 
   var callbackInfo = CallbackInfoNormalize(callback);
   if (IS_NULL(GetPendingObservers())) {
-    SetPendingObservers(nullProtoObject())
-    EnqueueMicrotask(ObserveMicrotaskRunner);
+    SetPendingObservers(nullProtoObject());
+    %EnqueueMicrotask(ObserveMicrotaskRunner);
   }
   GetPendingObservers()[callbackInfo.priority] = callback;
   callbackInfo.push(changeRecord);
 }
 
 function ObjectInfoEnqueueExternalChangeRecord(objectInfo, changeRecord, type) {
   if (!ObjectInfoHasActiveObservers(objectInfo))
     return;
 
   var hasType = !IS_UNDEFINED(type);
@@ skipping 196 matching lines @@
     "observe", ArrayObserve,
     "unobserve", ArrayUnobserve
   ));
   InstallFunctions(notifierPrototype, DONT_ENUM, $Array(
     "notify", ObjectNotifierNotify,
     "performChange", ObjectNotifierPerformChange
   ));
 }
 
 SetupObjectObserve();