Add OVERRIDE to chrome/browser/.

chrome/browser/tab_contents/background_contents.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_TAB_CONTENTS_BACKGROUND_CONTENTS_H_
 #define CHROME_BROWSER_TAB_CONTENTS_BACKGROUND_CONTENTS_H_
 #pragma once
 
 #include <string>
 
@@ skipping 38 matching lines @@
   virtual void CloseContents(TabContents* source) OVERRIDE;
   virtual bool ShouldSuppressDialogs() OVERRIDE;
   virtual void DidNavigateMainFramePostCommit(TabContents* tab) OVERRIDE;
 
   // TabContentsObserver implementation:
   virtual void RenderViewGone(base::TerminationStatus status) OVERRIDE;
 
   // content::NotificationObserver
   virtual void Observe(int type,
                        const content::NotificationSource& source,
-                       const content::NotificationDetails& details);
+                       const content::NotificationDetails& details) OVERRIDE;
 
  protected:
   // Exposed for testing.
   BackgroundContents();
 
  private:
   // The delegate for this BackgroundContents.
   Delegate* delegate_;
 
   Profile* profile_;
   scoped_ptr<TabContents> tab_contents_;
   content::NotificationRegistrar registrar_;
 
   DISALLOW_COPY_AND_ASSIGN(BackgroundContents);
 };
 
 // This is the data sent out as the details with BACKGROUND_CONTENTS_OPENED.
 struct BackgroundContentsOpenedDetails {
   // The BackgroundContents object that has just been opened.
   BackgroundContents* contents;
 
   // The name of the parent frame for these contents.
   const string16& frame_name;
 
   // The ID of the parent application (if any).
   const string16& application_id;
 };
 
 #endif  // CHROME_BROWSER_TAB_CONTENTS_BACKGROUND_CONTENTS_H_