Adds async interface method to PersistentPrefStore.

chrome/browser/prefs/pref_value_store.h

Index: chrome/browser/prefs/pref_value_store.h
diff --git a/chrome/browser/prefs/pref_value_store.h b/chrome/browser/prefs/pref_value_store.h
index 6a492ba19748949a2dd3357f94d7888560b2971f..bea3919db7a0dcbead875b00b2e9883948037312 100644
--- a/chrome/browser/prefs/pref_value_store.h
+++ b/chrome/browser/prefs/pref_value_store.h
@@ -152,7 +152,7 @@ class PrefValueStore {
    private:
     // PrefStore::Observer implementation.
     virtual void OnPrefValueChanged(const std::string& key);
-    virtual void OnInitializationCompleted();
+    virtual void OnInitializationCompleted(bool succeeded);
 
     // PrefValueStore this keeper is part of.
     PrefValueStore* pref_value_store_;
@@ -211,7 +211,7 @@ class PrefValueStore {
   void OnPrefValueChanged(PrefStoreType type, const std::string& key);
 
   // Handle the event that the store for |type| has completed initialization.
-  void OnInitializationCompleted(PrefStoreType type);
+  void OnInitializationCompleted(PrefStoreType type, bool succeeded);
 
   // Initializes a pref store keeper. Sets up a PrefStoreKeeper that will take
   // ownership of the passed |pref_store|.