Remove use of weakptr for RemovableDeviceNotificationsMac

chrome/browser/chrome_browser_main_mac.h

 // 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.
 
 #ifndef CHROME_BROWSER_CHROME_BROWSER_MAIN_MAC_H_
 #define CHROME_BROWSER_CHROME_BROWSER_MAIN_MAC_H_
 
 #include "chrome/browser/chrome_browser_main_posix.h"
+#include "base/memory/ref_counted.h"
 
 namespace chrome {
 class RemovableDeviceNotificationsMac;
 }
 
 class ChromeBrowserMainPartsMac : public ChromeBrowserMainPartsPosix {
  public:
   explicit ChromeBrowserMainPartsMac(
       const content::MainFunctionParams& parameters);
   virtual ~ChromeBrowserMainPartsMac();
 
   // BrowserParts overrides.
   virtual void PreEarlyInitialization() OVERRIDE;
   virtual void PreMainMessageLoopStart() OVERRIDE;
   virtual void PreProfileInit() OVERRIDE;
 
   // Perform platform-specific work that needs to be done after the main event
   // loop has ended. The embedder must be sure to call this.
   static void DidEndMainMessageLoop();
 
  private:
-  scoped_ptr<chrome::RemovableDeviceNotificationsMac>
+  scoped_refptr<chrome::RemovableDeviceNotificationsMac>
       removable_device_notifications_mac_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeBrowserMainPartsMac);
 };
 
 #endif  // CHROME_BROWSER_CHROME_BROWSER_MAIN_MAC_H_