Standardize usage of virtual/override/final in net/

net/url_request/static_http_user_agent_settings.h

Index: net/url_request/static_http_user_agent_settings.h
diff --git a/net/url_request/static_http_user_agent_settings.h b/net/url_request/static_http_user_agent_settings.h
index 4edb9480f0c9a05b4d3758aad7852cc33905c7b3..57bbd07b4c7696f47950a55ca4dc8b5629a1dcc5 100644
--- a/net/url_request/static_http_user_agent_settings.h
+++ b/net/url_request/static_http_user_agent_settings.h
@@ -20,11 +20,11 @@ class NET_EXPORT StaticHttpUserAgentSettings : public HttpUserAgentSettings {
  public:
   StaticHttpUserAgentSettings(const std::string& accept_language,
                               const std::string& user_agent);
-  virtual ~StaticHttpUserAgentSettings();
+  ~StaticHttpUserAgentSettings() override;
 
   // HttpUserAgentSettings implementation
-  virtual std::string GetAcceptLanguage() const override;
-  virtual std::string GetUserAgent() const override;
+  std::string GetAcceptLanguage() const override;
+  std::string GetUserAgent() const override;
 
  private:
   const std::string accept_language_;