Add OVERRIDE to chrome/browser/.

chrome/browser/user_style_sheet_watcher.h

 // Copyright (c) 2011 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_BROWSER_USER_STYLE_SHEET_WATCHER_H_
 #define CHROME_BROWSER_USER_STYLE_SHEET_WATCHER_H_
 #pragma once
 
 #include "base/file_path.h"
 #include "base/files/file_path_watcher.h"
@@ skipping 17 matching lines @@
  public:
   UserStyleSheetWatcher(Profile* profile, const FilePath& profile_path);
 
   void Init();
 
   GURL user_style_sheet() const;
 
   // content::NotificationObserver interface
   virtual void Observe(int type,
                        const content::NotificationSource& source,
-                       const content::NotificationDetails& details);
+                       const content::NotificationDetails& details) OVERRIDE;
 
  private:
   friend struct content::BrowserThread::DeleteOnThread<
       content::BrowserThread::UI>;
   friend class DeleteTask<UserStyleSheetWatcher>;
 
   virtual ~UserStyleSheetWatcher();
 
   // The profile owning us.
   Profile* profile_;
 
   // The directory containing User StyleSheets/Custom.css.
   FilePath profile_path_;
 
   // The loader object.
   scoped_refptr<UserStyleSheetLoader> loader_;
 
   // Watches for changes to the css file so we can reload the style sheet.
   scoped_ptr<base::files::FilePathWatcher> file_watcher_;
 
   content::NotificationRegistrar registrar_;
 
   DISALLOW_COPY_AND_ASSIGN(UserStyleSheetWatcher);
 };
 
 #endif  // CHROME_BROWSER_USER_STYLE_SHEET_WATCHER_H_