Update {virtual,override} to follow C++11 style in cloud_print.

cloud_print/gcp20/prototype/cloud_print_requester.h

Index: cloud_print/gcp20/prototype/cloud_print_requester.h
diff --git a/cloud_print/gcp20/prototype/cloud_print_requester.h b/cloud_print/gcp20/prototype/cloud_print_requester.h
index 91c24a085f516fbcd31fe2fa997459bdc89019ca..d916a4f65511f20c792e73571cb5def36caec96c 100644
--- a/cloud_print/gcp20/prototype/cloud_print_requester.h
+++ b/cloud_print/gcp20/prototype/cloud_print_requester.h
@@ -134,20 +134,20 @@ class CloudPrintRequester : public base::SupportsWeakPtr<CloudPrintRequester>,
   typedef base::Callback<void(const std::string&)> ParserCallback;
 
   // CloudPrintRequester::Delegate methods:
-  virtual void OnFetchComplete(const std::string& response) override;
-  virtual void OnFetchError(const std::string& server_api,
-                            int server_code,
-                            int server_http_code) override;
-  virtual void OnFetchTimeoutReached() override;
+  void OnFetchComplete(const std::string& response) override;
+  void OnFetchError(const std::string& server_api,
+                    int server_code,
+                    int server_http_code) override;
+  void OnFetchTimeoutReached() override;
 
   // gaia::GaiaOAuthClient::Delegate methods:
-  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;
 
   // Creates GET request.
   scoped_ptr<CloudPrintRequest> CreateGet(const GURL& url,