Adds async interface method to PersistentPrefStore.

chrome/browser/prefs/pref_notifier_impl.h

Index: chrome/browser/prefs/pref_notifier_impl.h
diff --git a/chrome/browser/prefs/pref_notifier_impl.h b/chrome/browser/prefs/pref_notifier_impl.h
index 085e547f64b1af35fafcf9881d1f1a280a23d7fc..28c1160f6ba8588c66bacbadb4d28aa798734cc5 100644
--- a/chrome/browser/prefs/pref_notifier_impl.h
+++ b/chrome/browser/prefs/pref_notifier_impl.h
@@ -32,7 +32,12 @@ class PrefNotifierImpl : public PrefNotifier,
   virtual void OnPreferenceChanged(const std::string& pref_name);
   virtual void OnInitializationCompleted();
 
+  void OnPersistentPrefsRead(bool success);
+
  protected:
+  void NotifyInitializationCompleted();
+  void NotifyInitializationFailed();
+
   // A map from pref names to a list of observers. Observers get fired in the
   // order they are added. These should only be accessed externally for unit
   // testing.
@@ -52,6 +57,9 @@ class PrefNotifierImpl : public PrefNotifier,
 
   PrefObserverMap pref_observers_;
 
+  bool pref_notifier_ready_;
+  bool persistent_prefs_ready_;
+
   DISALLOW_COPY_AND_ASSIGN(PrefNotifierImpl);
 };