"index" property should be optional with "chrome.tabs.move"

chrome/common/extensions/api/tabs.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": "tabs",
     "dependencies": [ "extension", "windows" ],
     "types": [
       {
@@ skipping 451 matching lines @@
             "name": "moveProperties",
             "properties": {
               "windowId": {
                 "type": "integer",
                 "minimum": -2,
                 "optional": true,
                 "description": "Defaults to the window the tab is currently in."
               },
               "index": {
                 "type": "integer",
-                "minimum": 0,
-                "description": "The position to move the window to. The provided value will be clamped to between zero and the number of tabs in the window."
+                "minimum": -1,
+                "description": "The position to move the window to. -1 will place the tab at the end of the window."
               }
             }
           },
           {
             "type": "function",
             "name": "callback",
             "optional": true,
             "parameters": [
               {
                 "name": "tabs",
@@ skipping 402 matching lines @@
             "name": "removeInfo",
             "properties": {
               "isWindowClosing": {"type": "boolean", "description": "True when the tab is being closed because its window is being closed." }
             }
           }
         ]
       }
     ]
   }
 ]