Adds syncedNotificationsPrivate API IDL.

chrome/common/extensions/api/api.gyp

 # 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.
 
 {
   'targets': [
     {
       'target_name': 'chrome_api',
       'type': 'static_library',
       'sources': [
@@ skipping 89 matching lines @@
               'preferences_private.json',
               'power.idl',
               'push_messaging.idl',
               'reading_list_private.json',
               'runtime.json',
               'serial.idl',
               'sessions.json',
               'signed_in_devices.idl',
               'streams_private.idl',
               'sync_file_system.idl',
+              'synced_notifications_private.idl',
               'system_cpu.idl',
               'system_display.idl',
               'system_indicator.idl',
               'system_memory.idl',
               'system_network.idl',
               'system_private.json',
               'system_storage.idl',
               'tab_capture.idl',
               'tabs.json',
               'terminal_private.json',
@@ skipping 68 matching lines @@
       'conditions': [
         ['chromeos==1', {
           'dependencies': [
             '<(DEPTH)/chrome/chrome.gyp:drive_proto',
           ],
         }],
       ],
     },
   ],
 }