chrome.settingsPrivate: Implement onPrefsChanged event handling.

chrome/browser/extensions/api/settings_private/settings_private_delegate.h

 // Copyright 2015 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_EXTENSIONS_API_SETTINGS_PRIVATE_SETTINGS_PRIVATE_DELEGATE_H_
 #define CHROME_BROWSER_EXTENSIONS_API_SETTINGS_PRIVATE_SETTINGS_PRIVATE_DELEGATE_H_
 
 #include <map>
 #include <string>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
-#include "chrome/browser/profiles/profile.h"
 #include "chrome/common/extensions/api/settings_private.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "extensions/browser/extension_function.h"
 
 class Profile;
 
 namespace base {
 class Value;
 }
 
@@ skipping 11 matching lines @@
 
   // Sets the pref with the given name and value in the proper PrefService.
   virtual bool SetPref(const std::string& name, const base::Value* value);
 
   // Gets the value of the pref with the given |name|.
   virtual scoped_ptr<base::Value> GetPref(const std::string& name);
 
   // Gets the values of all whitelisted prefs.
   virtual scoped_ptr<base::Value> GetAllPrefs();
 
- private:
-  PrefService* FindServiceForPref(const std::string& pref_name);
-
+ protected:
   Profile* profile_;  // weak; not owned by us
 
+ private:
   DISALLOW_COPY_AND_ASSIGN(SettingsPrivateDelegate);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_SETTINGS_PRIVATE_SETTINGS_PRIVATE_DELEGATE_H_