Adding Discarded property support for onUpdate function.

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",
     "description": "Use the <code>chrome.tabs</code> API to interact with the browser's tab system. You can use this API to create, modify, and rearrange tabs in the browser.",
     "types": [
       { "id": "MutedInfoReason",
@@ skipping 935 matching lines @@
               "pinned": {
                 "type": "boolean",
                 "optional": true,
                 "description": "The tab's new pinned state."
               },
               "audible": {
                 "type": "boolean",
                 "optional": true,
                 "description": "The tab's new audible state."
               },
+              "discarded": {
+                "type": "boolean",
+                "optional": true,
+                "description": "The tab's new discarded state."
+              },
               "mutedInfo": {
                 "$ref": "MutedInfo",
                 "optional": true,
                 "description": "The tab's new muted state and the reason for the change."
               },
               "favIconUrl": {
                 "type": "string",
                 "optional": true,
                 "description": "The tab's new favicon URL."
               },
@@ skipping 218 matching lines @@
             "tabId": {"type": "integer", "minimum": 0},
             "oldZoomFactor": {"type": "number"},
             "newZoomFactor": {"type": "number"},
             "zoomSettings": {"$ref": "ZoomSettings"}
           }
         }]
       }
     ]
   }
 ]