Apply FINAL to the RenderObject hierarchy.

Source/core/rendering/RenderTextFragment.h

Index: Source/core/rendering/RenderTextFragment.h
diff --git a/Source/core/rendering/RenderTextFragment.h b/Source/core/rendering/RenderTextFragment.h
index 3f86357ffb133fedf19426173a6f8c5c89f99f39..940f22eeaa63ab1f0d8716aa8faae1ada5a751a5 100644
--- a/Source/core/rendering/RenderTextFragment.h
+++ b/Source/core/rendering/RenderTextFragment.h
@@ -31,7 +31,7 @@ namespace WebCore {
 // first letter and that must therefore have different styles (and positions in the render tree).
 // We cache offsets so that text transformations can be applied in such a way that we can recover
 // the original unaltered string from our corresponding DOM node.
-class RenderTextFragment : public RenderText {
+class RenderTextFragment FINAL : public RenderText {
 public:
     RenderTextFragment(Node*, StringImpl*, int startOffset, int length);
     RenderTextFragment(Node*, StringImpl*);