Align HTMLImageElement relevant mutations to spec

third_party/WebKit/Source/core/html/HTMLPictureElement.cpp

 // 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.
 
 #include "config.h"
 #include "core/html/HTMLPictureElement.h"
 
 #include "core/HTMLNames.h"
 #include "core/dom/ElementTraversal.h"
 #include "core/frame/UseCounter.h"
 #include "core/html/HTMLImageElement.h"
+#include "core/html/HTMLSourceElement.h"
 #include "core/loader/ImageLoader.h"
 
 namespace blink {
 
 using namespace HTMLNames;
 
 inline HTMLPictureElement::HTMLPictureElement(Document& document)
     : HTMLElement(pictureTag, document)
 {
 }
 
 DEFINE_NODE_FACTORY(HTMLPictureElement)
 
-void HTMLPictureElement::sourceOrMediaChanged()
+void HTMLPictureElement::sourceOrMediaChanged(HTMLElement* sourceElement, Node* next)
 {
-    for (HTMLImageElement* imageElement = Traversal<HTMLImageElement>::firstChild(*this); imageElement; imageElement = Traversal<HTMLImageElement>::nextSibling(*imageElement)) {
-        imageElement->selectSourceURL(ImageLoader::UpdateNormal);
+    bool seenSource = false;
+    for (HTMLElement* element = Traversal<HTMLElement>::firstChild(*this); element; element = Traversal<HTMLElement>::nextSibling(*element)) {
+        if (sourceElement == element || (next && element == next))
+            seenSource = true;
+        if (isHTMLImageElement(element) && seenSource)
+            toHTMLImageElement(element)->selectSourceURL(ImageLoader::UpdateNormal);
     }
 }
 
 Node::InsertionNotificationRequest HTMLPictureElement::insertedInto(ContainerNode* insertionPoint)
 {
     UseCounter::count(document(), UseCounter::Picture);
     return HTMLElement::insertedInto(insertionPoint);
 }
 
 } // namespace