Remove support for the obsolete <isindex> tag.

Source/core/html/HTMLElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2011 Motorola Mobility. 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 81 matching lines @@
         || hasLocalName(baseTag)
         || hasLocalName(basefontTag)
         || hasLocalName(brTag)
         || hasLocalName(colTag)
         || hasLocalName(embedTag)
         || hasLocalName(frameTag)
         || hasLocalName(hrTag)
         || hasLocalName(imageTag)
         || hasLocalName(imgTag)
         || hasLocalName(inputTag)
-        || hasLocalName(isindexTag)
         || hasLocalName(linkTag)
         || hasLocalName(metaTag)
         || hasLocalName(paramTag)
         || hasLocalName(sourceTag)
         || hasLocalName(wbrTag))
         return true;
     return false;
 }
 
 static inline CSSValueID unicodeBidiAttributeForDirAuto(HTMLElement* element)
@@ skipping 857 matching lines @@
 #ifndef NDEBUG
 
 // For use in the debugger
 void dumpInnerHTML(WebCore::HTMLElement*);
 
 void dumpInnerHTML(WebCore::HTMLElement* element)
 {
     printf("%s\n", element->innerHTML().ascii().data());
 }
 #endif