Add [TypeChecking=Interface] to Node interface

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 1413 matching lines @@
     ASSERT_NOT_REACHED();
 }
 
 bool Node::offsetInCharacters() const
 {
     return isCharacterDataNode();
 }
 
 unsigned short Node::compareDocumentPosition(const Node* otherNode, ShadowTreesTreatment treatment) const
 {
-    // It is not clear what should be done if |otherNode| is nullptr.
-    if (!otherNode)
-        return DOCUMENT_POSITION_DISCONNECTED;
-
     if (otherNode == this)
         return DOCUMENT_POSITION_EQUIVALENT;
 
     const Attr* attr1 = nodeType() == ATTRIBUTE_NODE ? toAttr(this) : nullptr;
     const Attr* attr2 = otherNode->nodeType() == ATTRIBUTE_NODE ? toAttr(otherNode) : nullptr;
 
     const Node* start1 = attr1 ? attr1->ownerElement() : this;
     const Node* start2 = attr2 ? attr2->ownerElement() : otherNode;
 
     // If either of start1 or start2 is null, then we are disconnected, since one of the nodes is
@@ skipping 1008 matching lines @@
         node->showTreeForThis();
 }
 
 void showNodePath(const blink::Node* node)
 {
     if (node)
         node->showNodePathForThis();
 }
 
 #endif