Standardize usage of virtual/override/final in chrome/

chrome/test/perf/browser_perf_test.h

 // Copyright (c) 2012 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.
 
 #ifndef CHROME_TEST_PERF_BROWSER_PERF_TEST_H_
 #define CHROME_TEST_PERF_BROWSER_PERF_TEST_H_
 
 #include "chrome/test/base/in_process_browser_test.h"
 
 namespace base {
 class CommandLine;
 }
 
 class BrowserPerfTest : public InProcessBrowserTest {
  public:
   BrowserPerfTest();
   virtual ~BrowserPerfTest();
 
   // Set up common browser perf test flags. Typically call down to this if
   // overridden.
-  virtual void SetUpCommandLine(base::CommandLine* command_line) override;
+  void SetUpCommandLine(base::CommandLine* command_line) override;
 
   // Prints IO performance data for use by perf graphs.
   void PrintIOPerfInfo(const std::string& test_name);
 
   // Prints memory usage data for use by perf graphs.
   void PrintMemoryUsageInfo(const std::string& test_name);
 };
 
 #endif  // CHROME_TEST_PERF_BROWSER_PERF_TEST_H_