Fire load event for an image even if it was the last image we loaded successfully.

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 271 matching lines @@
         }
     } else {
         if (!imageSourceURL.isNull()) {
             // Fire an error event if the url string is not empty, but the KURL is.
             dispatchErrorEvent();
         }
         noImageResourceToLoad();
     }
 
     ImageResource* oldImage = m_image.get();
-    if (newImage != oldImage) {
-        sourceImageChanged();
+    bool resizingToViewport = updateBehavior == UpdateSizeChanged && m_element->layoutObject() && m_element->layoutObject()->isImage();
+    bool selectedNewImage = newImage != oldImage;

[esprehn, 2015/03/31 00:34:54]

I would just inline the newImage != oldImage check in the two places. It's just
a ptr compare.

+    if (resizingToViewport && !selectedNewImage) {

[esprehn, 2015/03/31 00:34:54]

I might add a method like isLayoutImage()

and then do:

if (updateBehavior == UpdateSizeChanged && isLayoutImage() && newImage ==
oldImage) {
   ...
} else {
   if (newImage != oldImage)
      sourceImageChanged()
}

[rhogan, 2015/03/31 19:03:19]

Mm, I passed on this. Hope that's OK.

+        toLayoutImage(m_element->layoutObject())->intrinsicSizeChanged();
+    } else {
+        if (selectedNewImage)
+            sourceImageChanged();
 
         if (m_hasPendingLoadEvent) {
             loadEventSender().cancelEvent(this);
             m_hasPendingLoadEvent = false;
         }
 
         // Cancel error events that belong to the previous load, which is now cancelled by changing the src attribute.
         // If newImage is null and m_hasPendingErrorEvent is true, we know the error event has been just posted by
         // this load and we should not cancel the event.
         // 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;
 
         updateRenderer();
         // If newImage exists and is cached, addClient() will result in the load event
         // being queued to fire. Ensure this happens after beforeload is dispatched.
         if (newImage)
             newImage->addClient(this);
 
         if (oldImage)
             oldImage->removeClient(this);
-    } else if (updateBehavior == UpdateSizeChanged && m_element->layoutObject() && m_element->layoutObject()->isImage()) {
-        toLayoutImage(m_element->layoutObject())->intrinsicSizeChanged();
     }
 
     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 261 matching lines @@
 #endif
 }
 
 #if ENABLE(OILPAN)
 ImageLoader::ImageLoaderClientRemover::~ImageLoaderClientRemover()
 {
     m_loader.willRemoveClient(m_client);
 }
 #endif
 }