Automagically generate :help key indexes.

common/modules/storage.jsm

@@ -347,6 +347,13 @@ var File = Class("File", {
         return array;
     },
 
+    /**
+     * Returns a new nsIFileURL object for this file.
+     *
+     * @returns {nsIFileURL}
+     */
+    toURI: function toURI() services.io.newFileURI(this),
+
     /**
      * Writes the string *buf* to this file.
      *