Introduce IncrementLoadEventDelayCount::clearAndCheckLoadEvent()

third_party/WebKit/Source/core/dom/IncrementLoadEventDelayCount.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef IncrementLoadEventDelayCount_h
 #define IncrementLoadEventDelayCount_h
 
 #include "platform/heap/Handle.h"
 #include "wtf/Allocator.h"
 #include "wtf/Noncopyable.h"
 #include <memory>
 
 namespace blink {
 
 class Document;
 
 // A helper class that will increment a document's loadEventDelayCount on
 // contruction and decrement it on destruction (semantics similar to RefPtr).
 class IncrementLoadEventDelayCount {
   USING_FAST_MALLOC(IncrementLoadEventDelayCount);
   WTF_MAKE_NONCOPYABLE(IncrementLoadEventDelayCount);
 
  public:
   static std::unique_ptr<IncrementLoadEventDelayCount> create(Document&);
   ~IncrementLoadEventDelayCount();
 
+  // Decrements the loadEventDelayCount and checks load event synchronously,
+  // and thus can cause synchronous Document load event/JavaScript execution.
+  // Call this only when it is safe, e.g. at the top of an async task.
+  // After calling this, |this| no longer blocks document's load event and
+  // will not decrement loadEventDelayCount at destruction.
+  void clearAndCheckLoadEvent();
+
   // Increments the new document's count and decrements the old count.
   void documentChanged(Document& newDocument);
 
  private:
   IncrementLoadEventDelayCount(Document&);
   Persistent<Document> m_document;
 };
 }  // namespace blink
 
 #endif