Support slotchange event

third_party/WebKit/Source/core/dom/Element.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Peter Kelly (pmk@post.com)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003-2011, 2013, 2014 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
@@ skipping 853 matching lines @@
     DCHECK(!needsStyleInvalidation());
     DCHECK(insertionPoint->inShadowIncludingDocument() || insertionPoint->isInShadowTree() || isContainerNode());
     if (insertionPoint->inShadowIncludingDocument()) {
         setFlag(InDocumentFlag);
         insertionPoint->document().incrementNodeCount();
     }
     if (parentOrShadowHostNode()->isInShadowTree())
         setFlag(IsInShadowTreeFlag);
     if (childNeedsDistributionRecalc() && !insertionPoint->childNeedsDistributionRecalc())
         insertionPoint->markAncestorsWithChildNeedsDistributionRecalc();
+    if (document().shadowCascadeOrder() == ShadowCascadeOrder::ShadowCascadeV1) {

[hayato, 2016/04/18 07:16:31]

Given that CSS is no longer only the client of this flag, 
it would be better to rename shadowCascadeOrder to more general name.

[yuzuchan, 2016/04/18 09:43:27]

Found out that I do not need to use the function here. Will rename it in another
CL.

+        if (isChildOfV1ShadowHost() || isChildOfSlot())
+            document().updateAssignment();
+    }
     return InsertionDone;
 }
 
 inline void Node::removedFrom(ContainerNode* insertionPoint)
 {
     DCHECK(insertionPoint->inShadowIncludingDocument() || isContainerNode() || isInShadowTree());
     if (insertionPoint->inShadowIncludingDocument()) {
         clearFlag(InDocumentFlag);
         insertionPoint->document().decrementNodeCount();
     }
@@ skipping 77 matching lines @@
     static T* create(const QualifiedName&, Document&)
 #define DEFINE_ELEMENT_FACTORY_WITH_TAGNAME(T) \
     T* T::create(const QualifiedName& tagName, Document& document) \
     { \
         return new T(tagName, document); \
     }
 
 } // namespace blink
 
 #endif // Element_h