Introduce toHTMLInputElement(Node*), and use it.

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 599 matching lines @@
     unsigned short compareDocumentPosition(const Node*) const;
 
     enum ShadowTreesTreatment {
         TreatShadowTreesAsDisconnected,
         TreatShadowTreesAsComposed
     };
 
     unsigned short compareDocumentPositionInternal(const Node*, ShadowTreesTreatment) const;
 
     virtual Node* toNode();
+    // Obsolete. Use toHTMLInputElement.
     virtual HTMLInputElement* toInputElement();
 
     virtual const AtomicString& interfaceName() const;
     virtual ScriptExecutionContext* scriptExecutionContext() const;
 
     virtual bool addEventListener(const AtomicString& eventType, PassRefPtr<EventListener>, bool useCapture);
     virtual bool removeEventListener(const AtomicString& eventType, EventListener*, bool useCapture);
 
     // Handlers to do/undo actions on the target node before an event is dispatched to it and after the event
     // has been dispatched.  The data pointer is handed back by the preDispatch and passed to postDispatch.
@@ skipping 277 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