Have the browser process confirm creation of a persistent notification.

content/common/platform_notification_messages.h

 // Copyright 2014 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.
 
 // Messages for platform-native notifications using the Web Notification API.
 // Multiply-included message file, hence no include guard.
 
 #include <stdint.h>
 #include <string>
 #include <utility>
@@ skipping 41 matching lines @@
                      int /* notification_id */)
 
 // Informs the renderer that the notification has been closed.
 IPC_MESSAGE_CONTROL1(PlatformNotificationMsg_DidClose,
                      int /* notification_id */)
 
 // Informs the renderer that the notification has been clicked on.
 IPC_MESSAGE_CONTROL1(PlatformNotificationMsg_DidClick,
                      int /* notification_id */)
 
+// Reply to PlatformNotificationHostMsg_ShowPersistent indicating that a
+// persistent notification has been shown on the platform (if |success| is
+// true), or that an unspecified error occurred.
+IPC_MESSAGE_CONTROL2(PlatformNotificationMsg_DidShowPersistent,
+                     int /* request_id */,
+                     bool /* success */)
+
 // Reply to PlatformNotificationHostMsg_GetNotifications sharing a vector of
 // available notifications per the request's constraints.
 IPC_MESSAGE_CONTROL2(PlatformNotificationMsg_DidGetNotifications,
                      int /* request_id */,
                      std::vector<PersistentNotificationInfo>
                          /* notifications */)
 
 // Messages sent from the renderer to the browser.
 
 IPC_MESSAGE_CONTROL4(PlatformNotificationHostMsg_Show,
                      int /* notification_id */,
                      GURL /* origin */,
                      SkBitmap /* icon */,
                      content::PlatformNotificationData /* notification_data */)
 
-IPC_MESSAGE_CONTROL4(PlatformNotificationHostMsg_ShowPersistent,
+IPC_MESSAGE_CONTROL5(PlatformNotificationHostMsg_ShowPersistent,
+                     int /* request_id */,
                      int64_t /* service_worker_registration_id */,
                      GURL /* origin */,
                      SkBitmap /* icon */,
                      content::PlatformNotificationData /* notification_data */)
 
 IPC_MESSAGE_CONTROL4(PlatformNotificationHostMsg_GetNotifications,
                      int /* request_id */,
                      int64_t /* service_worker_registration_id */,
                      GURL /* origin */,
                      std::string /* filter_tag */)
 
 IPC_MESSAGE_CONTROL1(PlatformNotificationHostMsg_Close,
                      int /* notification_id */)
 
 IPC_MESSAGE_CONTROL2(PlatformNotificationHostMsg_ClosePersistent,
                      GURL /* origin */,
                      std::string /* persistent_notification_id */)
 
 IPC_SYNC_MESSAGE_CONTROL1_1(PlatformNotificationHostMsg_CheckPermission,
                             GURL /* origin */,
                             blink::WebNotificationPermission /* result */)