Update rendering classes to use OVERRIDE / FINAL when needed

Source/core/rendering/RenderDetailsMarker.h

Index: Source/core/rendering/RenderDetailsMarker.h
diff --git a/Source/core/rendering/RenderDetailsMarker.h b/Source/core/rendering/RenderDetailsMarker.h
index aa996c818a2a45e72344c7f5a214393af5147c2e..6876cda71b73f5ba7cba9ee467d56c3a80d9f0db 100644
--- a/Source/core/rendering/RenderDetailsMarker.h
+++ b/Source/core/rendering/RenderDetailsMarker.h
@@ -34,10 +34,10 @@ public:
     Orientation orientation() const;
 
 private:
-    virtual const char* renderName() const { return "RenderDetailsMarker"; }
+    virtual const char* renderName() const OVERRIDE { return "RenderDetailsMarker"; }
     virtual bool supportsPartialLayout() const OVERRIDE { return false; }
-    virtual bool isDetailsMarker() const { return true; }
-    virtual void paint(PaintInfo&, const LayoutPoint&);
+    virtual bool isDetailsMarker() const OVERRIDE { return true; }
+    virtual void paint(PaintInfo&, const LayoutPoint&) OVERRIDE;
 
     bool isOpen() const;
     Path getCanonicalPath() const;