Minimize RenderObject* casting to RenderText*

Source/core/rendering/RenderText.h

Index: Source/core/rendering/RenderText.h
diff --git a/Source/core/rendering/RenderText.h b/Source/core/rendering/RenderText.h
index bcaba48bdb803ef97a61a09243563eb1f0c5d4cb..fcb4ca838246269c5bac5e546eb619078bc63c72 100644
--- a/Source/core/rendering/RenderText.h
+++ b/Source/core/rendering/RenderText.h
@@ -1,7 +1,7 @@
 /*
  * (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
@@ -23,6 +23,7 @@
 #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"
@@ -230,6 +231,11 @@ inline void RenderText::checkConsistency() const
 }
 #endif
 
+inline RenderText* Text::renderer() const
+{
+    return toRenderText(CharacterData::renderer());
+}
+
 void applyTextTransform(const RenderStyle*, String&, UChar);
 
 } // namespace blink