This adds the onNetworkChanged event to networkingPrivate

chrome/common/extensions/api/networking_private.json

 // Copyright (c) 2013 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":"networkingPrivate",
     "compiler_options": {
       "implemented_in": "chrome/browser/chromeos/extensions/networking_private_api.h"
     },
@@ skipping 81 matching lines @@
           },
           {
             "name": "callback",
             "type": "function",
             "optional": true,
             "parameters": [],
             "description": "A callback function that indicates that a disconnect has been initiated."
           }
         ]
       }
+    ],
+    "events": [
+      {
+        "name": "onNetworkChanged",
+        "type": "function",
+        "description": "Fired when the properties change on any of the networks.  Only contains the networks that changed, but each item contains all the properties for the changed network.",
+        "parameters": [
+          {
+            "name": "changes",
+            "type": "array",
+            "items": { "$ref": "NetworkProperties" }
+          }
+        ]
+      }
     ]
   }
 ]