Adds async interface method to PersistentPrefStore.

chrome/common/persistent_pref_store.h

Index: chrome/common/persistent_pref_store.h
diff --git a/chrome/common/persistent_pref_store.h b/chrome/common/persistent_pref_store.h
index 620fee8fabdce6839b0132a36408a6ec207a4a75..3b812c881d8cdb21fe65f8a731b9a76450e894f3 100644
--- a/chrome/common/persistent_pref_store.h
+++ b/chrome/common/persistent_pref_store.h
@@ -62,9 +62,17 @@ class PersistentPrefStore : public PrefStore {
   // read errors during startup.
   virtual bool ReadOnly() const = 0;
 
-  // Reads the preferences from disk.
+  // Reads the preferences from disk. Notifies observers via
+  // "OnInitializationCompleted" when done.
   virtual PrefReadError ReadPrefs() = 0;
 
+  // Reads the preferences from disk asynchronously. Notifies observers via
+  // "OnInitializationCompleted" when done.
+  virtual void ReadPrefsAsync() = 0;
+
+  // Returns reading error and whether the error is fatal.
+  virtual void GetErrors(PrefReadError* error, bool* is_fatal) = 0;
+
   // Writes the preferences to disk immediately.
   virtual bool WritePrefs() = 0;