Revert of Use v8::MicrotasksScope internally in V8RecursionScope.

third_party/WebKit/Source/core/dom/Microtask.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 22 matching lines @@
 #include "bindings/core/v8/V8PerIsolateData.h"
 #include "platform/ScriptForbiddenScope.h"
 #include "platform/Task.h"
 #include "public/platform/WebTaskRunner.h"
 #include <v8.h>
 
 namespace blink {
 
 void Microtask::performCheckpoint(v8::Isolate* isolate)
 {
-    if (ScriptForbiddenScope::isScriptForbidden())
+    V8PerIsolateData* isolateData = V8PerIsolateData::from(isolate);
+    ASSERT(isolateData);
+    if (isolateData->recursionLevel() || isolateData->performingMicrotaskCheckpoint() || isolateData->destructionPending() || ScriptForbiddenScope::isScriptForbidden())
         return;
-    v8::MicrotasksScope::PerformCheckpoint(isolate);
+    isolateData->setPerformingMicrotaskCheckpoint(true);
+    isolate->RunMicrotasks();
+    isolateData->setPerformingMicrotaskCheckpoint(false);
 }
 
 static void microtaskFunctionCallback(void* data)
 {
     OwnPtr<WebTaskRunner::Task> task = adoptPtr(static_cast<WebTaskRunner::Task*>(data));
     task->run();
 }
 
 void Microtask::enqueueMicrotask(PassOwnPtr<WebTaskRunner::Task> callback)
 {
     v8::Isolate* isolate = v8::Isolate::GetCurrent();
     isolate->EnqueueMicrotask(&microtaskFunctionCallback, callback.leakPtr());
 }
 
 void Microtask::enqueueMicrotask(PassOwnPtr<SameThreadClosure> callback)
 {
     enqueueMicrotask(adoptPtr(new SameThreadTask(callback)));
 }
 
 } // namespace blink