Update references to the extension messaging APIs to point to the "runtime"

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",
     "nodoc": "true",
     "types": [
       {
@@ skipping 819 matching lines @@
           },
           {
             "name": "destinationFileUrl",
             "type": "string",
             "description": "Destination file on the remote file system."
           },
           {
             "name": "callback",
             "type": "function",
             "optional": true,
-            "description": "Completion callback. chrome.extension.lastError will be set if there was an error.",
+            "description": "Completion callback. chrome.runtime.lastError will be set if there was an error.",
             "parameters": []
           }
         ]
       },
       {
         "name": "cancelFileTransfers",
         "description": "Cancels ongoing file transfers for selected files.",
         "parameters": [
           {
             "name": "fileUrls",
@@ skipping 26 matching lines @@
           },
           {
             "name": "lastModified",
             "type": "string",
             "description": "Date to set as last modification date in ms. Should be passed to C++ as string, since 'long' type isn't supported"
           },
           {
             "name": "callback",
             "type": "function",
             "optional": true,
-            "description": "Completion callback. chrome.extension.lastError will be set if there was an error.",
+            "description": "Completion callback. chrome.runtime.lastError will be set if there was an error.",
             "parameters": []
           }
         ]
       },
       {
         "name": "getSizeStats",
         "description": "Retrieves total and remaining size of a mount point.",
         "parameters": [
           {
             "name": "mountPath",
@@ skipping 286 matching lines @@
       },
       {
         "name": "onNetworkConnectionChanged",
         "type": "function",
         "description": "Fired when the active network connection state changes. The network connection state can be retrieved via 'getNetworkConnectionState'.",
         "parameters": []
       }
     ]
   }
 ]