Adds async interface method to PersistentPrefStore.

content/common/notification_type.h

Index: content/common/notification_type.h
diff --git a/content/common/notification_type.h b/content/common/notification_type.h
index f0cf97642389beeba8c6c769d0baad364f6f23ff..bf17728bb2db4ef62b809a8cab9c4baef8031c62 100644
--- a/content/common/notification_type.h
+++ b/content/common/notification_type.h
@@ -746,6 +746,10 @@ class NotificationType {
     // asynchronous initalization of a PrefService.
     PREF_INITIALIZATION_COMPLETED,
 
+    // This is broadcast after the preference subsystem has failed to load a
+    // PrefService.
+    PREF_INITIALIZATION_FAILED,

[Mattias Nissler (ping if slow), 2011/04/27 12:16:30]

As mention elsewhere, I think it's much better to pass a Details parameter
instead.

[altimofeev, 2011/05/04 13:46:14]

Done.

+
     // Sent when a default request context has been created, so calling
     // Profile::GetDefaultRequestContext() will not return NULL.  This is sent
     // on the thread where Profile::GetRequestContext() is first called, which