Revert of Remove EventSender from ImageLoader

third_party/WebKit/Source/core/loader/ImageLoader.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2009 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  *
  */
 
 #ifndef ImageLoader_h
 #define ImageLoader_h
 
 #include <memory>
 #include "core/CoreExport.h"
-#include "core/dom/TaskRunnerHelper.h"
 #include "core/loader/resource/ImageResource.h"
 #include "core/loader/resource/ImageResourceContent.h"
 #include "core/loader/resource/ImageResourceObserver.h"
 #include "platform/heap/Handle.h"
 #include "platform/wtf/HashSet.h"
 #include "platform/wtf/WeakPtr.h"
 #include "platform/wtf/text/AtomicString.h"
 
 namespace blink {
 
 class IncrementLoadEventDelayCount;
 class Element;
 class ImageLoader;
 class LayoutImageResource;
 
+template <typename T>
+class EventSender;
+using ImageEventSender = EventSender<ImageLoader>;
+
 class CORE_EXPORT ImageLoader : public GarbageCollectedFinalized<ImageLoader>,
                                 public ImageResourceObserver {
   USING_PRE_FINALIZER(ImageLoader, Dispose);
 
  public:
   explicit ImageLoader(Element*);
   ~ImageLoader() override;
 
   DECLARE_TRACE();
 
@@ skipping 48 matching lines @@
   //   Normal loading via ResourceFetcher/ResourceLoader.
   //   |image_resource_for_image_document_| is null.
   bool IsLoadingImageDocument() { return loading_image_document_; }
   void SetLoadingImageDocument() { loading_image_document_ = true; }
   ImageResource* ImageResourceForImageDocument() const {
     return image_resource_for_image_document_;
   }
 
   bool HasPendingActivity() const { return HasPendingEvent() || pending_task_; }
 
-  bool HasPendingError() const { return pending_error_event_.IsActive(); }
+  bool HasPendingError() const { return has_pending_error_event_; }
 
   bool HadError() const { return !failed_load_url_.IsEmpty(); }
 
+  void DispatchPendingEvent(ImageEventSender*);
+
+  static void DispatchPendingLoadEvents();
+  static void DispatchPendingErrorEvents();
+
   bool GetImageAnimationPolicy(ImageAnimationPolicy&) final;
 
  protected:
   void ImageChanged(ImageResourceContent*, const IntRect*) override;
   void ImageNotifyFinished(ImageResourceContent*) override;
 
  private:
   class Task;
 
   // Called from the task or from updateFromElement to initiate the load.
   void DoUpdateFromElement(BypassMainWorldBehavior,
                            UpdateFromElementBehavior,
                            const KURL&,
                            ReferrerPolicy = kReferrerPolicyDefault);
 
   virtual void DispatchLoadEvent() = 0;
   virtual void NoImageResourceToLoad() {}
 
   bool HasPendingEvent() const;
   void UpdatedHasPendingEvent();
 
-  void DispatchPendingLoadEvent(std::unique_ptr<IncrementLoadEventDelayCount>);
-  void DispatchPendingErrorEvent(std::unique_ptr<IncrementLoadEventDelayCount>);
+  void DispatchPendingLoadEvent();
+  void DispatchPendingErrorEvent();
 
   LayoutImageResource* GetLayoutImageResource();
   void UpdateLayoutObject();
 
   // Note: SetImage.*() are not a simple setter.
   // Check the implementation to see what they do.
   // TODO(hiroshige): Cleanup these methods.
   void SetImageForImageDocument(ImageResource*);
   void SetImageWithoutConsideringPendingLoadEvent(ImageResourceContent*);
   void UpdateImageState(ImageResourceContent*);
@@ skipping 42 matching lines @@
   // and we delay Document load event from (1) to (3):
   // - |ResourceFetcher::loaders_| delays Document load event from (1) to (2).
   // - |delay_until_image_notify_finished_| delays Document load event from
   //   the first ImageChanged() (at some time between (1) and (2)) until (3).
   // Ideally, we might want to delay Document load event from (1) to (3),
   // but currently we piggyback on ImageChanged() because adding a callback
   // hook at (1) might complicate the code.
   std::unique_ptr<IncrementLoadEventDelayCount>
       delay_until_image_notify_finished_;
 
-  TaskHandle pending_load_event_;
-  TaskHandle pending_error_event_;
+  // Indicates whether there is a pending task for the load/error event on
+  // EventSender. Will be replaced when EventSender is removed crbug/624697.
+  bool has_pending_load_event_ : 1;
+  bool has_pending_error_event_ : 1;
 
   bool image_complete_ : 1;
   bool loading_image_document_ : 1;
   bool element_is_protected_ : 1;
   bool suppress_error_events_ : 1;
 };
 
 }  // namespace blink
 
 #endif