Introduce Node::needsDistributionRecalc and use it in ElementShadow to fix the wrong assertions.

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 647 matching lines @@
         return node.document();
     Node* root = &node;
     while (Node* host = root->shadowHost())
         root = host;
     while (Node* ancestor = root->parentNode())
         root = ancestor;
     ASSERT(!root->shadowHost());
     return *root;
 }
 
+#if ENABLE(ASSERT)
+bool Node::needsDistributionRecalc() const
+{
+    // TODO(hayato): If we can prove that this->childNeedsDistributionRecalc()
+    // is enough for either case, in a document, not in a document, remove this
+    // function after renaming Node::childNeedsDistributionRecalc() to a more
+    // appropriate name.
+    if (inDocument())
+        return document().childNeedsDistributionRecalc();
+    return childNeedsDistributionRecalc();
+}
+#endif
+
 void Node::updateDistribution()
 {
     TRACE_EVENT0("blink", "Node::updateDistribution");
     ScriptForbiddenScope forbidScript;
     rootInTreeOfTrees(*this).recalcDistribution();
 }
 
 void Node::recalcDistribution()
 {
     if (isElementNode()) {
@@ skipping 1815 matching lines @@
         node->showTreeForThis();
 }
 
 void showNodePath(const blink::Node* node)
 {
     if (node)
         node->showNodePathForThis();
 }
 
 #endif