Standardize usage of virtual/override/final in cc/

cc/debug/traced_picture.h

Index: cc/debug/traced_picture.h
diff --git a/cc/debug/traced_picture.h b/cc/debug/traced_picture.h
index 1d31694a0d334378fad342bf9e1790fd7d793e07..b5f5e3ae134b750068bdf604c8d2d636fb46380c 100644
--- a/cc/debug/traced_picture.h
+++ b/cc/debug/traced_picture.h
@@ -23,10 +23,10 @@ class TracedPicture : public base::debug::ConvertableToTraceFormat {
   static scoped_refptr<base::debug::ConvertableToTraceFormat>
       AsTraceablePictureAlias(const Picture* original);
 
-  virtual void AppendAsTraceFormat(std::string* out) const override;
+  void AppendAsTraceFormat(std::string* out) const override;
 
  private:
-  virtual ~TracedPicture();
+  ~TracedPicture() override;
 
   void AppendPicture(std::string* out) const;
   void AppendPictureAlias(std::string* out) const;