Implement getting notifications up to the browser process.

content/browser/notifications/notification_message_filter.h

Index: content/browser/notifications/notification_message_filter.h
diff --git a/content/browser/notifications/notification_message_filter.h b/content/browser/notifications/notification_message_filter.h
index b860acfa8a2ac30c2655ceb840832a8ac8582f74..ad9072877a723964ce896acff965ffb8b0ee57c8 100644
--- a/content/browser/notifications/notification_message_filter.h
+++ b/content/browser/notifications/notification_message_filter.h
@@ -55,6 +55,10 @@ class NotificationMessageFilter : public BrowserMessageFilter {
       const GURL& origin,
       const SkBitmap& icon,
       const PlatformNotificationData& notification_data);
+  void OnGetNotifications(int request_id,
+                          int64_t service_worker_registration_id,
+                          const GURL& origin,
+                          const std::string& filter_tag);
   void OnClosePlatformNotification(int notification_id);
   void OnClosePersistentNotification(
       const GURL& origin,