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

content/browser/time_zone_monitor_win.cc

 // Copyright 2014 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 "content/browser/time_zone_monitor.h"
 
 #include <windows.h>
 
 #include "base/basictypes.h"
 #include "ui/gfx/win/singleton_hwnd.h"
 
 namespace content {
 
 class TimeZoneMonitorWin : public TimeZoneMonitor,
                            public gfx::SingletonHwnd::Observer {
  public:
   TimeZoneMonitorWin() : TimeZoneMonitor() {
     gfx::SingletonHwnd::GetInstance()->AddObserver(this);
   }
 
-  virtual ~TimeZoneMonitorWin() {
+  ~TimeZoneMonitorWin() override {
     gfx::SingletonHwnd::GetInstance()->RemoveObserver(this);
   }
 
   // gfx::SingletonHwnd::Observer implementation.
-  virtual void OnWndProc(HWND hwnd,
-                         UINT message,
-                         WPARAM wparam,
-                         LPARAM lparam) override {
+  void OnWndProc(HWND hwnd,
+                 UINT message,
+                 WPARAM wparam,
+                 LPARAM lparam) override {
     if (message != WM_TIMECHANGE) {
       return;
     }
 
     NotifyRenderers();
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(TimeZoneMonitorWin);
 };
 
 // static
 scoped_ptr<TimeZoneMonitor> TimeZoneMonitor::Create() {
   return scoped_ptr<TimeZoneMonitor>(new TimeZoneMonitorWin());
 }
 
 }  // namespace content