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

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2009, 2010 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 158 matching lines @@
 
 void ImageLoader::dispose() {
   RESOURCE_LOADING_DVLOG(1)
       << "~ImageLoader " << this
       << "; m_hasPendingLoadEvent=" << m_hasPendingLoadEvent
       << ", m_hasPendingErrorEvent=" << m_hasPendingErrorEvent;
 
   if (m_image) {
     m_image->removeObserver(this);
     m_image = nullptr;
+    m_loadDelayCounter2 = nullptr;
   }
 }
 
 DEFINE_TRACE(ImageLoader) {
   visitor->trace(m_image);
   visitor->trace(m_imageResourceForImageDocument);
   visitor->trace(m_element);
 }
 
 void ImageLoader::setImage(ImageResourceContent* newImage) {
   setImageWithoutConsideringPendingLoadEvent(newImage);
 
   // Only consider updating the protection ref-count of the Element immediately
   // before returning from this function as doing so might result in the
   // destruction of this ImageLoader.
   updatedHasPendingEvent();
 }
 
 void ImageLoader::setImageWithoutConsideringPendingLoadEvent(
     ImageResourceContent* newImage) {
   DCHECK(m_failedLoadURL.isEmpty());
   ImageResourceContent* oldImage = m_image.get();
   if (newImage != oldImage) {
     m_image = newImage;
+    m_loadDelayCounter2 = nullptr;
     if (m_hasPendingLoadEvent) {
       loadEventSender().cancelEvent(this);
       m_hasPendingLoadEvent = false;
     }
     if (m_hasPendingErrorEvent) {
       errorEventSender().cancelEvent(this);
       m_hasPendingErrorEvent = false;
     }
     m_imageComplete = true;
     if (newImage) {
@@ skipping 139 matching lines @@
     // FIXME: If both previous load and this one got blocked with an error, we
     // can receive one error event instead of two.
     if (m_hasPendingErrorEvent && newImage) {
       errorEventSender().cancelEvent(this);
       m_hasPendingErrorEvent = false;
     }
 
     m_image = newImage;
     m_hasPendingLoadEvent = newImage;
     m_imageComplete = !newImage;
+    m_loadDelayCounter2 = nullptr;
 
     updateLayoutObject();
     // If newImage exists and is cached, addObserver() will result in the load
     // event being queued to fire. Ensure this happens after beforeload is
     // dispatched.
+    if (oldImage) {
+      oldImage->removeObserver(this);
+    }
     if (newImage) {

[fs, 2017/03/15 14:22:17]

This shuffle is non-obvious, what are the side-effects of removeObserver and
addObserver (some of the side-effects of addObserver is described above, maybe
that needs some updating too?)

[hiroshige, 2017/05/04 22:50:50]

Oh, this was my mistake (unintentionally changed the code while refactoring).
Reverted.

       newImage->addObserver(this);
     }
-    if (oldImage) {
-      oldImage->removeObserver(this);
-    }
   }
 
   if (LayoutImageResource* imageResource = layoutImageResource())
     imageResource->resetAnimation();
 
   // Only consider updating the protection ref-count of the Element immediately
   // before returning from this function as doing so might result in the
   // destruction of this ImageLoader.
   updatedHasPendingEvent();
 }
@@ skipping 33 matching lines @@
   KURL url = imageSourceToKURL(imageSourceURL);
   if (shouldLoadImmediately(url)) {
     doUpdateFromElement(DoNotBypassMainWorldCSP, updateBehavior, url,
                         referrerPolicy);
     return;
   }
   // Allow the idiom "img.src=''; img.src='.." to clear down the image before an
   // asynchronous load completes.
   if (imageSourceURL.isEmpty()) {
     ImageResourceContent* image = m_image.get();
-    if (image) {
+    if (image)
       image->removeObserver(this);
-    }
     m_image = nullptr;
+    m_loadDelayCounter2 = nullptr;
   }
 
   // Don't load images for inactive documents. We don't want to slow down the
   // raw HTML parsing case by loading images we don't intend to display.
   Document& document = m_element->document();
   if (document.isActive())
     enqueueImageLoadingMicroTask(updateBehavior, referrerPolicy);
 }
 
 KURL ImageLoader::imageSourceToKURL(AtomicString imageSourceURL) const {
@@ skipping 22 matching lines @@
   // content when style recalc is over and DOM mutation is allowed again.
   if (!url.isNull()) {
     Resource* resource = memoryCache()->resourceForURL(
         url, m_element->document().fetcher()->getCacheIdentifier());
     if (resource && !resource->errorOccurred())
       return true;
   }
   return (isHTMLObjectElement(m_element) || isHTMLEmbedElement(m_element));
 }
 
+void ImageLoader::imageChanged(ImageResourceContent* content, const IntRect*) {
+  DCHECK_EQ(content, m_image.get());
+  if (m_imageComplete || !content->isLoading() || m_loadDelayCounter2)
+    return;
+
+  Document& document = m_element->document();
+  if (!document.isActive())
+    return;
+
+  m_loadDelayCounter2 = IncrementLoadEventDelayCount::create(document);
+}
+
 void ImageLoader::imageNotifyFinished(ImageResourceContent* resource) {
   RESOURCE_LOADING_DVLOG(1)
       << "ImageLoader::imageNotifyFinished " << this
       << "; m_hasPendingLoadEvent=" << m_hasPendingLoadEvent;
 
   DCHECK(m_failedLoadURL.isEmpty());
   DCHECK_EQ(resource, m_image.get());
 
   m_imageComplete = true;
+  m_loadDelayCounter2 = nullptr;
 
   // Update ImageAnimationPolicy for m_image.
   if (m_image)
     m_image->updateImageAnimationPolicy();
 
   updateLayoutObject();
 
   if (m_image && m_image->getImage() && m_image->getImage()->isSVGImage())
     toSVGImage(m_image->getImage())->updateUseCounters(element()->document());
 
@@ skipping 138 matching lines @@
   loadEventSender().dispatchPendingEvents();
 }
 
 void ImageLoader::dispatchPendingErrorEvents() {
   errorEventSender().dispatchPendingEvents();
 }
 
 void ImageLoader::elementDidMoveToNewDocument() {
   if (m_loadDelayCounter)
     m_loadDelayCounter->documentChanged(m_element->document());
+  if (m_loadDelayCounter2)
+    m_loadDelayCounter2->documentChanged(m_element->document());
   clearFailedLoadURL();
   setImage(0);
 }
 
 }  // namespace blink