Clean up pref change notification handling.

chrome/test/testing_pref_value_store.h

-// Copyright (c) 2010 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_TEST_TESTING_PREF_VALUE_STORE_H_
-#define CHROME_TEST_TESTING_PREF_VALUE_STORE_H_
-#pragma once
-
-#include "chrome/browser/prefs/pref_value_store.h"
-
-// PrefValueStore subclass that allows directly setting PrefStores.
-class TestingPrefValueStore : public PrefValueStore {
- public:
-  TestingPrefValueStore(PrefStore* managed_platform_prefs,
-                        PrefStore* device_management_prefs,
-                        PrefStore* extension_prefs,
-                        PrefStore* command_line_prefs,
-                        PrefStore* user_prefs,
-                        PrefStore* recommended_prefs,
-                        PrefStore* default_prefs)
-      : PrefValueStore(managed_platform_prefs, device_management_prefs,
-                       extension_prefs, command_line_prefs,
-                       user_prefs, recommended_prefs, default_prefs, NULL) {}
-};
-
-#endif  // CHROME_TEST_TESTING_PREF_VALUE_STORE_H_