Simplify fileBrowserPrivate.getDriveConnectionStatus().

chrome/common/extensions/api/file_browser_private.json

 // 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.
 
 [
   {
     "namespace":"fileBrowserPrivate",
     "compiler_options": {
       "implemented_in": "chrome/browser/chromeos/extensions/file_manager/file_browser_private_api_functions.h"
     },
@@ skipping 929 matching lines @@
         "parameters": [
           {
             "name": "callback",
             "type": "function",
             "parameters": [
               {
                 "name": "result",
                 "type": "object",
                 "properties": {
                   "type": {"type": "string"},
-                  "reasons": {
-                    "type": "array",
+                  "reason": {
+                    "type": "string",
                     "description": "Reasons of offline.",
-                    "items": { "type": "string" }
+                    "optional": true
                   }
                 }
               }
             ]
           }
         ]
       },
       {
         "name": "validatePathNameLength",
         "description": "Checks whether the path name length fits in the limit of the filesystem.",
@@ skipping 203 matching lines @@
       },
       {
         "name": "onDriveConnectionStatusChanged",
         "type": "function",
         "description": "Fired when the active network connection state changes. The network connection state can be retrieved via 'getDriveConnectionState'.",
         "parameters": []
       }
     ]
   }
 ]