Minimize RenderObject* casting to RenderText*

Source/core/rendering/RenderText.h

 /*
  * (C) 1999 Lars Knoll (knoll@kde.org)
  * (C) 2000 Dirk Mueller (mueller@kde.org)
- * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
+ * Copyright (C) 2004-2009, 2013 Apple Inc. 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
  * 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
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  *
  */
 
 #ifndef RenderText_h
 #define RenderText_h
 
+#include "core/dom/Text.h"
 #include "core/rendering/RenderObject.h"
 #include "platform/LengthFunctions.h"
 #include "platform/text/TextPath.h"
 #include "wtf/Forward.h"
 #include "wtf/PassRefPtr.h"
 
 namespace blink {
 
 class AbstractInlineTextBox;
 class InlineTextBox;
@@ skipping 187 matching lines @@
 }
 
 DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderText, isText());
 
 #if !ENABLE(ASSERT)
 inline void RenderText::checkConsistency() const
 {
 }
 #endif
 
+inline RenderText* Text::renderer() const
+{
+    return toRenderText(CharacterData::renderer());
+}
+
 void applyTextTransform(const RenderStyle*, String&, UChar);
 
 } // namespace blink
 
 #endif // RenderText_h