Standardize usage of virtual/override/final in chrome/

chrome/test/base/browser_tests_main.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <algorithm>
 
 #include "base/sys_info.h"
 #include "chrome/test/base/chrome_test_launcher.h"
 #include "chrome/test/base/chrome_test_suite.h"
 
 class ChromeBrowserTestSuiteRunner : public ChromeTestSuiteRunner {
  public:
-  virtual int RunTestSuite(int argc, char** argv) override {
+  int RunTestSuite(int argc, char** argv) override {
     return ChromeTestSuite(argc, argv).Run();
   }
 };
 
 int main(int argc, char** argv) {
   int default_jobs = std::max(1, base::SysInfo::NumberOfProcessors() / 2);
   ChromeBrowserTestSuiteRunner runner;
   return LaunchChromeTests(default_jobs, &runner, argc, argv);
 }