Gather stability prefs into managing objects.

components/metrics/clean_exit_beacon.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 COMPONENTS_METRICS_CLEAN_EXIT_BEACON_H_
 #define COMPONENTS_METRICS_CLEAN_EXIT_BEACON_H_
 
 #include "base/macros.h"
 #include "base/strings/string16.h"
 
+class PrefRegistrySimple;
 class PrefService;
 
 namespace metrics {
 
 // Reads and updates a beacon used to detect whether the previous browser
 // process exited cleanly.
 class CleanExitBeacon {
  public:
   // Instantiates a CleanExitBeacon whose value is stored in |local_state|.
   // |local_state| must be fully initialized.
   // On Windows, |backup_registry_key| is used to store a backup of the beacon.
   // It is ignored on other platforms.
   CleanExitBeacon(
       const base::string16& backup_registry_key,
       PrefService* local_state);
 
   ~CleanExitBeacon();
 
   // Returns the original value of the beacon.
   bool exited_cleanly() const { return initial_value_; }
 
   // Writes the provided beacon value.
   void WriteBeaconValue(bool exited_cleanly);
 
+  // Registers local state prefs used by this class.
+  static void RegisterPrefs(PrefRegistrySimple* registry);
+
  private:
   PrefService* const local_state_;
   const bool initial_value_;
   const base::string16 backup_registry_key_;
 
   DISALLOW_COPY_AND_ASSIGN(CleanExitBeacon);
 };
 
 }  // namespace metrics
 
 #endif  // COMPONENTS_METRICS_CLEAN_EXIT_BEACON_H_