[CSS Regions] Elements in a region should be assignable to a named flow

Source/core/dom/Node.h

 /*
  * 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, 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
  * License as published by the Free Software Foundation; either
@@ skipping 252 matching lines @@
 
     bool isDocumentNode() const;
     bool isTreeScope() const { return treeScope()->rootNode() == this; }
     bool isDocumentFragment() const { return getFlag(IsDocumentFragmentFlag); }
     bool isShadowRoot() const { return isDocumentFragment() && isTreeScope(); }
     bool isInsertionPoint() const { return getFlag(IsInsertionPointFlag); }
 
     bool inNamedFlow() const { return getFlag(InNamedFlowFlag); }
     bool hasCustomStyleCallbacks() const { return getFlag(HasCustomStyleCallbacksFlag); }
 
+    bool isRegisteredWithNamedFlow() const;
+
     bool hasSyntheticAttrChildNodes() const { return getFlag(HasSyntheticAttrChildNodesFlag); }
     void setHasSyntheticAttrChildNodes(bool flag) { setFlag(flag, HasSyntheticAttrChildNodesFlag); }
 
     // If this node is in a shadow tree, returns its shadow host. Otherwise, returns 0.
     Element* shadowHost() const;
     // If this node is in a shadow tree, returns its shadow host. Otherwise, returns this.
     // Deprecated. Should use shadowHost() and check the return value.
     Node* deprecatedShadowAncestorNode() const;
     ShadowRoot* containingShadowRoot() const;
     ShadowRoot* youngestShadowRoot() const;
@@ skipping 648 matching lines @@
 
 } //namespace
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showTree(const WebCore::Node*);
 void showNodePath(const WebCore::Node*);
 #endif
 
 #endif