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 07a5b6127694d6f19b4f4301f109b73fdfa8c987..5d3d5bb787bf9a602d39e613cc5fa8f3e99fdec1 100644
--- a/chrome/browser/prefs/pref_value_store.h
+++ b/chrome/browser/prefs/pref_value_store.h
@@ -155,7 +155,7 @@ 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_;
@@ -214,7 +214,7 @@ 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|.
@@ -247,6 +247,9 @@ class PrefValueStore {
   // A mapping of preference names to their registered types.
   PrefTypeMap pref_types_;
 
+  // True if not all of the PrefStores were initialized successfully.
+  bool initialization_failed_;
+
   DISALLOW_COPY_AND_ASSIGN(PrefValueStore);
 };