Convert //extensions/{common,shell} from scoped_ptr to std::unique_ptr

extensions/shell/browser/shell_prefs.h

 // 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.
 
 #ifndef EXTENSIONS_SHELL_BROWSER_SHELL_PREFS_H_
 #define EXTENSIONS_SHELL_BROWSER_SHELL_PREFS_H_
 
-#include "base/memory/scoped_ptr.h"
+#include <memory>
 
 class PrefService;
 
 namespace base {
 class FilePath;
 }
 
 namespace content {
 class BrowserContext;
 }
 
 namespace extensions {
 
 // Support for preference initialization and management.
 namespace shell_prefs {
 
 // Creates a pref service for device-wide preferences stored in |data_dir|.
-scoped_ptr<PrefService> CreateLocalState(const base::FilePath& data_dir);
+std::unique_ptr<PrefService> CreateLocalState(const base::FilePath& data_dir);
 
 // Creates a pref service that loads user preferences for |browser_context|.
-scoped_ptr<PrefService> CreateUserPrefService(
+std::unique_ptr<PrefService> CreateUserPrefService(
     content::BrowserContext* browser_context);
 
 }  // namespace shell_prefs
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_SHELL_BROWSER_SHELL_PREFS_H_