Rewrite Shadow DOM distribution engine to support partial synchronous distribution for v1

third_party/WebKit/Source/core/dom/ContainerNode.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, 2013 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 675 matching lines @@
     notifyNodeInserted(*newChild, ChildrenChangeSourceParser);
 }
 
 void ContainerNode::notifyNodeInserted(Node& root, ChildrenChangeSource source)
 {
 #if DCHECK_IS_ON()
     DCHECK(!EventDispatchForbiddenScope::isEventDispatchForbidden());
 #endif
     DCHECK(!root.isShadowRoot());
 
+    if (document().containsV1ShadowTree())
+        root.checkSlotChangeAfterInserted();
+
     InspectorInstrumentation::didInsertDOMNode(&root);
 
     NodeVector postInsertionNotificationTargets;
     notifyNodeInsertedInternal(root, postInsertionNotificationTargets);
 
     childrenChanged(ChildrenChange::forInsertion(root, source));
 
     for (const auto& targetNode : postInsertionNotificationTargets) {
         if (targetNode->inShadowIncludingDocument())
             targetNode->didNotifySubtreeInsertionsToDocument();
@@ skipping 679 matching lines @@
         return true;
 
     if (node->isElementNode() && toElement(node)->shadow())
         return true;
 
     return false;
 }
 #endif
 
 } // namespace blink