Standardize usage of virtual/override/final in chrome/browser/supervised_user/

chrome/browser/supervised_user/supervised_user_refresh_token_fetcher.cc

Index: chrome/browser/supervised_user/supervised_user_refresh_token_fetcher.cc
diff --git a/chrome/browser/supervised_user/supervised_user_refresh_token_fetcher.cc b/chrome/browser/supervised_user/supervised_user_refresh_token_fetcher.cc
index 8605050d8e218059758010b0f6ca8f40be796cd5..5c526c432549dce24bea7f04404984311bfe511d 100644
--- a/chrome/browser/supervised_user/supervised_user_refresh_token_fetcher.cc
+++ b/chrome/browser/supervised_user/supervised_user_refresh_token_fetcher.cc
@@ -60,32 +60,32 @@ class SupervisedUserRefreshTokenFetcherImpl
       const std::string& account_id,
       const std::string& device_id,
       URLRequestContextGetter* context);
-  virtual ~SupervisedUserRefreshTokenFetcherImpl();
+  ~SupervisedUserRefreshTokenFetcherImpl() override;
 
   // SupervisedUserRefreshTokenFetcher implementation:
-  virtual void Start(const std::string& supervised_user_id,
-                     const std::string& device_name,
-                     const TokenCallback& callback) override;
+  void Start(const std::string& supervised_user_id,
+             const std::string& device_name,
+             const TokenCallback& callback) override;
 
  protected:
   // OAuth2TokenService::Consumer implementation:
-  virtual void OnGetTokenSuccess(const OAuth2TokenService::Request* request,
-                                 const std::string& access_token,
-                                 const Time& expiration_time) override;
-  virtual void OnGetTokenFailure(const OAuth2TokenService::Request* request,
-                                 const GoogleServiceAuthError& error) override;
+  void OnGetTokenSuccess(const OAuth2TokenService::Request* request,
+                         const std::string& access_token,
+                         const Time& expiration_time) override;
+  void OnGetTokenFailure(const OAuth2TokenService::Request* request,
+                         const GoogleServiceAuthError& error) override;
 
   // net::URLFetcherDelegate implementation.
-  virtual void OnURLFetchComplete(const URLFetcher* source) override;
+  void OnURLFetchComplete(const URLFetcher* source) override;
 
   // GaiaOAuthClient::Delegate implementation:
-  virtual void OnGetTokensResponse(const std::string& refresh_token,
-                                   const std::string& access_token,
-                                   int expires_in_seconds) override;
-  virtual void OnRefreshTokenResponse(const std::string& access_token,
-                                      int expires_in_seconds) override;
-  virtual void OnOAuthError() override;
-  virtual void OnNetworkError(int response_code) override;
+  void OnGetTokensResponse(const std::string& refresh_token,
+                           const std::string& access_token,
+                           int expires_in_seconds) override;
+  void OnRefreshTokenResponse(const std::string& access_token,
+                              int expires_in_seconds) override;
+  void OnOAuthError() override;
+  void OnNetworkError(int response_code) override;
 
  private:
   // Requests an access token, which is the first thing we need. This is where