Mac Chromium style checker cleanup

chrome/browser/ui/cocoa/extensions/extension_installed_bubble_controller.mm

 // 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.
 
 #import "chrome/browser/ui/cocoa/extensions/extension_installed_bubble_controller.h"
 
 #include "base/i18n/rtl.h"
 #include "base/mac/bundle_locations.h"
 #include "base/mac/mac_util.h"
 #include "base/sys_string_conversions.h"
@@ skipping 49 matching lines @@
           : controller_(controller) {
     registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_LOADED,
         content::Source<Profile>(profile));
     registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_UNLOADED,
         content::Source<Profile>(profile));
   }
 
  private:
   // NotificationObserver implementation. Tells the controller to start showing
   // its window on the main thread when the extension has finished loading.
-  void Observe(int type,
-               const content::NotificationSource& source,
-               const content::NotificationDetails& details) {
+  virtual void Observe(
+      int type,
+      const content::NotificationSource& source,
+      const content::NotificationDetails& details) OVERRIDE {
     if (type == chrome::NOTIFICATION_EXTENSION_LOADED) {
       const Extension* extension =
           content::Details<const Extension>(details).ptr();
       if (extension == [controller_ extension]) {
         [controller_ performSelectorOnMainThread:@selector(showWindow:)
                                       withObject:controller_
                                    waitUntilDone:NO];
       }
     } else if (type == chrome::NOTIFICATION_EXTENSION_UNLOADED) {
       const Extension* extension =
@@ skipping 614 matching lines @@
   ExtensionInstallUI::OpenAppInstalledUI(browser_, extension_->id());
 }
 
 - (void)awakeFromNib {
   if (bundle_)
     return;
   [self initializeLabel];
 }
 
 @end