Phase III Step 2: Call imageNotifyFinished() and image load event after SVG loading completes

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.
  *
@@ skipping 93 matching lines @@
   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);
@@ skipping 34 matching lines @@
   Member<ImageResourceContent> image_;
   Member<ImageResource> image_resource_for_image_document_;
   // FIXME: Oilpan: We might be able to remove this Persistent hack when
   // ImageResourceClient is traceable.
   GC_PLUGIN_IGNORE("http://crbug.com/383741")
   Persistent<Element> keep_alive_;
 
   Timer<ImageLoader> deref_element_timer_;
   AtomicString failed_load_url_;
   WeakPtr<Task> pending_task_;  // owned by Microtask
-  std::unique_ptr<IncrementLoadEventDelayCount> load_delay_counter_;
+  std::unique_ptr<IncrementLoadEventDelayCount>
+      delay_until_do_update_from_element_;
+
+  // Delaying load event: the timeline should be:
+  // (0) ImageResource::Fetch() is called.
+  // (1) ResourceFetcher::StartLoad(): Resource loading is actually started.
+  // (2) ResourceLoader::DidFinishLoading() etc:
+  //         Resource loading is finished, but SVG document load might be
+  //         incomplete because of asynchronously loaded subresources.
+  // (3) ImageNotifyFinished(): Image is completely loaded.
+  // 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_;
+
   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