Update the behavior of ShadowRoot.activeElement to match the latest spec

third_party/WebKit/Source/core/dom/Node.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 825 matching lines @@
         return false;
 
     for (; node; node = node->shadowHost()) {
         if (treeScope() == node->treeScope())
             return contains(node);
     }
 
     return false;
 }
 
+Node* Node::retarget(const Node& target) const
+{
+    for (const Node* ancestor = ⌖ ancestor; ancestor = ancestor->shadowHost()) {
+        if (treeScope() == ancestor->treeScope())
+            return const_cast<Node*>(ancestor);
+    }
+    return nullptr;
+}
+
 bool Node::containsIncludingHostElements(const Node& node) const
 {
     const Node* current = &node;
     do {
         if (current == this)
             return true;
         if (current->isDocumentFragment() && toDocumentFragment(current)->isTemplateContent())
             current = static_cast<const TemplateContentDocumentFragment*>(current)->host();
         else
             current = current->parentOrShadowHostNode();
@@ skipping 1591 matching lines @@
 
 void showNodePath(const blink::Node* node)
 {
     if (node)
         node->showNodePathForThis();
     else
         fprintf(stderr, "Cannot showNodePath for (nil)\n");
 }
 
 #endif