Hook up API to notification_ui_manager.

chrome/common/extensions/api/experimental_notification.idl

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 [nodoc] namespace experimental.notification {
   dictionary ShowOptions {
-    DOMString text;
+    DOMString iconUrl;
+    DOMString title;
+    DOMString message;
+    DOMString replaceId;
 
     // Used for internal event routing. Do not set or rely on its value.
     [nodoc] long? srcId;
   };
 
   dictionary ShowInfo {
+    boolean result;
   };
 
   callback ShowCallback = void (ShowInfo showInfo);
 
   interface Functions {
     static void show(ShowOptions options, ShowCallback callback);
   };
 
 };