Create a DefaultPrefStore to hold registered application-default preference v...

chrome/browser/prefs/pref_notifier.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_BROWSER_PREFS_PREF_NOTIFIER_H_
 #define CHROME_BROWSER_PREFS_PREF_NOTIFIER_H_
 #pragma once
 
 #include <string>
 #include <vector>
@@ skipping 14 matching lines @@
 // preference) change.
 class PrefNotifier : public NonThreadSafe,
                      public NotificationObserver {
  public:
   // PrefStores must be listed here in order from highest to lowest priority.
   //   MANAGED contains all managed (policy) preference values.
   //   EXTENSION contains preference values set by extensions.
   //   COMMAND_LINE contains preference values set by command-line switches.
   //   USER contains all user-set preference values.
   //   RECOMMENDED contains all recommended (policy) preference values.
+  //   DEFAULT contains all application default preference values.
   // This enum is kept in pref_notifier.h rather than pref_value_store.h in
   // order to minimize additional headers needed by the *PrefStore files.
   enum PrefStoreType {
     // INVALID_STORE is not associated with an actual PrefStore but used as
     // an invalid marker, e.g. as a return value.
     INVALID_STORE = -1,
     MANAGED_STORE = 0,
     EXTENSION_STORE,
     COMMAND_LINE_STORE,
     USER_STORE,
     RECOMMENDED_STORE,
-    PREF_STORE_TYPE_MAX = RECOMMENDED_STORE
+    DEFAULT_STORE,
+    PREF_STORE_TYPE_MAX = DEFAULT_STORE
   };
 
   // The |service| with which this notifier is associated will be sent as the
   // source of any notifications.
   PrefNotifier(PrefService* service, PrefValueStore* value_store);
 
   virtual ~PrefNotifier();
 
-  // For the given pref_name, fire any observer of the pref if |old_value| is
-  // different from the current value, or if the store controlling the value
-  // has changed.
-  // TODO(pamg): Currently notifies in some cases when it shouldn't. See
-  // comments for PrefHasChanged() in pref_value_store.h.
+  // For the given pref_name, fire any observer of the pref if the effective
+  // value of the pref or the store controlling its value has changed, been
+  // added, or been removed (but not if it's re-setting the same value it had
+  // already). |new_store| should be the PrefStoreType of the store reporting
+  // the change.
   void OnPreferenceSet(const char* pref_name,
-                       PrefNotifier::PrefStoreType new_store,
-                       const Value* old_value);
+                       PrefNotifier::PrefStoreType new_store);
 
   // Convenience method to be called when a preference is set in the
   // USER_STORE. See OnPreferenceSet().
-  void OnUserPreferenceSet(const char* pref_name, const Value* old_value);
+  void OnUserPreferenceSet(const char* pref_name);
 
   // For the given pref_name, fire any observer of the pref. Virtual so it can
   // be mocked for unit testing.
   virtual void FireObservers(const char* path);
 
   // If the pref at the given path changes, we call the observer's Observe
   // method with NOTIFY_PREF_CHANGED.
   void AddPrefObserver(const char* path, NotificationObserver* obs);
   void RemovePrefObserver(const char* path, NotificationObserver* obs);
 
@@ skipping 26 matching lines @@
 
   // NotificationObserver methods:
   virtual void Observe(NotificationType type,
                        const NotificationSource& source,
                        const NotificationDetails& details);
 
   DISALLOW_COPY_AND_ASSIGN(PrefNotifier);
 };
 
 #endif  // CHROME_BROWSER_PREFS_PREF_NOTIFIER_H_