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

chrome/browser/chrome_browser_main_posix.cc

 // 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.
 
 #include "chrome/browser/chrome_browser_main_posix.h"
 
 #include <errno.h>
 #include <limits.h>
 #include <pthread.h>
 #include <signal.h>
@@ skipping 77 matching lines @@
 // ExitHandler takes care of servicing an exit (from a signal) at the
 // appropriate time. Specifically if we get an exit and have not finished
 // session restore we delay the exit. To do otherwise means we're exiting part
 // way through startup which causes all sorts of problems.
 class ExitHandler : public content::NotificationObserver {
  public:
   // Invokes exit when appropriate.
   static void ExitWhenPossibleOnUIThread();
 
   // Overridden from content::NotificationObserver:
-  virtual void Observe(int type,
-                       const content::NotificationSource& source,
-                       const content::NotificationDetails& details) override;
+  void Observe(int type,
+               const content::NotificationSource& source,
+               const content::NotificationDetails& details) override;
 
  private:
   ExitHandler();
-  virtual ~ExitHandler();
+  ~ExitHandler() override;
 
   // Does the appropriate call to Exit.
   static void Exit();
 
   content::NotificationRegistrar registrar_;
 
   DISALLOW_COPY_AND_ASSIGN(ExitHandler);
 };
 
 // static
@@ skipping 36 matching lines @@
   chrome::ExitCleanly();
 #else
   chrome::AttemptExit();
 #endif
 }
 
 class ShutdownDetector : public base::PlatformThread::Delegate {
  public:
   explicit ShutdownDetector(int shutdown_fd);
 
-  virtual void ThreadMain() override;
+  void ThreadMain() override;
 
  private:
   const int shutdown_fd_;
 
   DISALLOW_COPY_AND_ASSIGN(ShutdownDetector);
 };
 
 ShutdownDetector::ShutdownDetector(int shutdown_fd)
     : shutdown_fd_(shutdown_fd) {
   CHECK_NE(shutdown_fd_, -1);
@@ skipping 144 matching lines @@
   // Not called on Mac because we load the locale files differently.
   NOTREACHED();
 #elif defined(USE_AURA)
   // TODO(port): We may want a views based message dialog here eventually, but
   // for now, crash.
   NOTREACHED();
 #else
 #error "Need MessageBox implementation."
 #endif
 }