Restore sessionStorage when chrome restarts.

content/public/browser/notification_types.h

Index: content/public/browser/notification_types.h
diff --git a/content/public/browser/notification_types.h b/content/public/browser/notification_types.h
index 363df21a7d4ce5517eb36472e4c29d71f2d86a1b..a2017ab4f2105fc028d82f55a3b5626672812b96 100644
--- a/content/public/browser/notification_types.h
+++ b/content/public/browser/notification_types.h
@@ -412,6 +412,12 @@ enum NotificationType {
   // of a temporary zoom level change, the details is an empty string.
   NOTIFICATION_ZOOM_LEVEL_CHANGED,
 
+  // Sent when a |DOMStorageNamespace| for sessionStorage is created. The source
+  // is the |DOMStorageMessageFilter| which initiated the creation of the
+  // |DOMStorageNamespace|. The details are in a
+  // |Details<SessionStorageNamespaceCreatedDetails>|.
+  NOTIFICATION_SESSION_STORAGE_NAMESPACE_CREATED,
+
   // Custom notifications used by the embedder should start from here.
   NOTIFICATION_CONTENT_END,
 };