Add initial support for native Linux desktop notifications

chrome/browser/flag_descriptions.cc

 // Copyright 2017 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.
 
 #include "chrome/browser/flag_descriptions.h"
 
 namespace flag_descriptions {
 
 //  Material Design version of chrome://bookmarks
 
@@ skipping 2871 matching lines @@
 
 const char kEnableEhvInputName[] =
     "Emoji, handwriting and voice input on opt-in IME menu";
 
 const char kEnableEhvInputDescription[] =
     "Enable access to emoji, handwriting and voice input form opt-in IME "
     "menu.";
 
 #endif  // #if defined(OS_CHROMEOS)
 
+#if defined(OS_LINUX) && !defined(OS_CHROMEOS)
+const char kUseSystemNotificationsName[] =
+    "Use Freedesktop system notifications";
+
+const char kUseSystemNotificationsDescription[] =
+    "Send notifications to the notification center supplied by the Linux "
+    "desktop environment instead of using Chrome-rendered notifications.";
+#endif
+
 }  // namespace flag_descriptions