Use new is*Element() helper functions more in rendering code

Source/core/rendering/RenderMeter.cpp

 /*
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
  *
  * 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
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 26 matching lines @@
 }
 
 RenderMeter::~RenderMeter()
 {
 }
 
 HTMLMeterElement* RenderMeter::meterElement() const
 {
     ASSERT(node());
 
-    if (node()->hasTagName(meterTag))
+    if (isHTMLMeterElement(*node()))
         return toHTMLMeterElement(node());
 
     ASSERT(node()->shadowHost());
     return toHTMLMeterElement(node()->shadowHost());
 }
 
 void RenderMeter::updateLogicalWidth()
 {
     RenderBox::updateLogicalWidth();
 
@@ skipping 18 matching lines @@
 {
     return meterElement()->valueRatio();
 }
 
 void RenderMeter::updateFromElement()
 {
     repaint();
 }
 
 } // namespace WebCore