Revert of Delete base/prefs and update callers to use components.

components/prefs/pref_notifier.h

 // Copyright (c) 2011 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 COMPONENTS_PREFS_PREF_NOTIFIER_H_
-#define COMPONENTS_PREFS_PREF_NOTIFIER_H_
+#ifndef BASE_PREFS_PREF_NOTIFIER_H_
+#define BASE_PREFS_PREF_NOTIFIER_H_
 
 #include <string>
 
 // Delegate interface used by PrefValueStore to notify its owner about changes
 // to the preference values.
 // TODO(mnissler, danno): Move this declaration to pref_value_store.h once we've
 // cleaned up all public uses of this interface.
 class PrefNotifier {
  public:
   virtual ~PrefNotifier() {}
 
   // Sends out a change notification for the preference identified by
   // |pref_name|.
   virtual void OnPreferenceChanged(const std::string& pref_name) = 0;
 
   // Broadcasts the intialization completed notification.
   virtual void OnInitializationCompleted(bool succeeded) = 0;
 };
 
-#endif  // COMPONENTS_PREFS_PREF_NOTIFIER_H_
+#endif  // BASE_PREFS_PREF_NOTIFIER_H_