Use isHTML*Element() helpers more in the accessibility code

Source/core/accessibility/AXMediaControls.cpp

 /*
  * Copyright (C) 2009 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 241 matching lines @@
 }
 
 PassRefPtr<AXObject> AccessibilityMediaTimeline::create(RenderObject* renderer)
 {
     return adoptRef(new AccessibilityMediaTimeline(renderer));
 }
 
 String AccessibilityMediaTimeline::valueDescription() const
 {
     Node* node = m_renderer->node();
-    if (!node->hasTagName(inputTag))
+    if (!isHTMLInputElement(node))
         return String();
 
     return localizedMediaTimeDescription(toHTMLInputElement(node)->value().toFloat());
 }
 
 String AccessibilityMediaTimeline::helpText() const
 {
     return queryString(WebLocalizedString::AXMediaSliderHelp);
 }
 
@@ skipping 33 matching lines @@
 {
     if (!m_renderer || !m_renderer->node())
         return String();
 
     MediaControlTimeDisplayElement* element = static_cast<MediaControlTimeDisplayElement*>(m_renderer->node());
     float time = element->currentValue();
     return localizedMediaTimeDescription(fabsf(time));
 }
 
 } // namespace WebCore