Remove content::NotificationObserver dependency from most Prefs code.

chrome/browser/prefs/pref_service.h

 // Copyright (c) 2012 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.
 
 // This provides a way to access the application's current preferences.
 
 // Chromium settings and storage represent user-selected preferences and
 // information and MUST not be extracted, overwritten or modified except
 // through Chromium defined APIs.
 
 #ifndef CHROME_BROWSER_PREFS_PREF_SERVICE_H_
 #define CHROME_BROWSER_PREFS_PREF_SERVICE_H_
 
 #include <set>
 #include <string>
 
+#include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/hash_tables.h"
 #include "base/observer_list.h"
 #include "base/prefs/public/pref_service_base.h"
 #include "base/threading/non_thread_safe.h"
 
 class CommandLine;
 class DefaultPrefStore;
 class PersistentPrefStore;
 class PrefModelAssociator;
 class PrefNotifier;
 class PrefNotifierImpl;
+class PrefObserver;
 class PrefServiceObserver;
 class PrefStore;
 class PrefValueStore;
 
 namespace base {
   class SequencedTaskRunner;
 }
 
 namespace syncer {
 class SyncableService;
@@ skipping 230 matching lines @@
   PrefInitializationStatus GetInitializationStatus() const;
 
   // syncer::SyncableService getter.
   // TODO(zea): Have PrefService implement syncer::SyncableService directly.
   syncer::SyncableService* GetSyncableService();
 
   // Tell our PrefValueStore to update itself using |command_line|.
   // Do not call this after having derived an incognito or per tab pref service.
   void UpdateCommandLinePrefStore(CommandLine* command_line);
 
+  // We run the callback once, when initialization completes. The bool
+  // parameter will be set to true for successful initialization,
+  // false for unsuccessful.
+  void AddPrefInitObserver(base::Callback<void(bool)> callback);
+
  protected:
   // Construct a new pref service. This constructor is what
   // factory methods end up calling and what is used for unit tests.
   PrefService(PrefNotifierImpl* pref_notifier,
               PrefValueStore* pref_value_store,
               PersistentPrefStore* user_prefs,
               DefaultPrefStore* default_store,
               PrefModelAssociator* pref_sync_associator,
               bool async);
 
   // The PrefNotifier handles registering and notifying preference observers.
   // It is created and owned by this PrefService. Subclasses may access it for
   // unit testing.
   scoped_ptr<PrefNotifierImpl> pref_notifier_;
 
  private:
   // Hash map expected to be fastest here since it minimises expensive
   // string comparisons. Order is unimportant, and deletions are rare.
   // Confirmed on Android where this speeded Chrome startup by roughly 50ms
   // vs. std::map, and by roughly 180ms vs. std::set of Preference pointers.
   typedef base::hash_map<std::string, Preference> PreferenceMap;
 
   friend class PrefServiceMockBuilder;
 
   // Give access to ReportUserPrefChanged() and GetMutableUserPref().
   friend class subtle::ScopedUserPrefUpdateBase;
 
   // PrefServiceBase implementation (protected in base, private here).
   virtual void AddPrefObserver(const char* path,
-                               content::NotificationObserver* obs) OVERRIDE;
+                               PrefObserver* obs) OVERRIDE;
   virtual void RemovePrefObserver(const char* path,
-                                  content::NotificationObserver* obs) OVERRIDE;
+                                  PrefObserver* obs) OVERRIDE;
 
   // Sends notification of a changed preference. This needs to be called by
   // a ScopedUserPrefUpdate if a DictionaryValue or ListValue is changed.
   void ReportUserPrefChanged(const std::string& key);
 
   // Registers a new preference at |path|. The |default_value| must not be
   // NULL as it determines the preference value's type.
   // RegisterPreference must not be called twice for the same path.
   // This method takes ownership of |default_value|.
   void RegisterPreference(const char* path,
@@ skipping 38 matching lines @@
   // CreatePrefServiceWithPerTabPrefStore() have been called to create a
   // "forked" PrefService.
   bool pref_service_forked_;
 
   ObserverList<PrefServiceObserver> observer_list_;
 
   DISALLOW_COPY_AND_ASSIGN(PrefService);
 };
 
 #endif  // CHROME_BROWSER_PREFS_PREF_SERVICE_H_