Reduce number of expensive calls to List.redraw() during load of settings page.

chrome/browser/resources/options2/chromeos/network_list.js

 // 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.
 
 cr.define('options.network', function() {
 
   var ArrayDataModel = cr.ui.ArrayDataModel;
   var List = cr.ui.List;
   var ListItem = cr.ui.ListItem;
   var Menu = cr.ui.Menu;
@@ skipping 710 matching lines @@
    * @constructor
    */
   var NetworkList = cr.ui.define('list');
 
   NetworkList.prototype = {
     __proto__: List.prototype,
 
     /** @inheritDoc */
     decorate: function() {
       List.prototype.decorate.call(this);
+      this.startBatchUpdates();
       this.autoExpands = true;
       this.addEventListener('blur', this.onBlur_);
       this.dataModel = new ArrayDataModel([]);
 
       // Wi-Fi control is always visible.
       this.update({key: 'wifi', networkList: []});
 
       if (airplaneModeAvailable_()) {
         this.update({key: 'airplaneMode',
                      subtitle: loadTimeData.getString('airplaneModeLabel'),
@@ skipping 16 matching lines @@
                            command: addConnection(Constants.TYPE_WIFI)},
                           {label: loadTimeData.getString('addConnectionVPN'),
                            command: addConnection(Constants.TYPE_VPN)}]
                   });
 
       var prefs = options.Preferences.getInstance();
       prefs.addEventListener('cros.signed.data_roaming_enabled',
           function(event) {
             enableDataRoaming_ = event.value.value;
           });
+      this.endBatchUpdates();
     },
 
     /**
      * When the list loses focus, unselect all items in the list and close the
      * active menu.
      * @private
      */
     onBlur_: function() {
       this.selectionModel.unselectAll();
       closeMenu_();
@@ skipping 94 matching lines @@
     }
   };
 
   /**
    * Chrome callback for updating network controls.
    * @param {Object} data Description of available network devices and their
    *     corresponding state.
    */
   NetworkList.refreshNetworkData = function(data) {
     var networkList = $('network-list');
+    networkList.startBatchUpdates();
     cellularAvailable_ = data.cellularAvailable;
     cellularEnabled_ = data.cellularEnabled;
     wimaxAvailable_ = data.wimaxAvailable;
     wimaxEnabled_ = data.wimaxEnabled;
 
     if (data.accessLocked) {
       $('network-locked-message').hidden = false;
       networkList.disabled = true;
       $('use-shared-proxies').disabled = true;
     } else {
@@ skipping 68 matching lines @@
     }
 
     // Only show VPN control if there is an available network and an internet
     // connection.
     if (data.vpnList.length > 0 && (ethernetConnection ||
         isConnected_(data.wirelessList)))
       loadData_('vpn', data.vpnList, data.rememberedList);
     else
       networkList.deleteItem('vpn');
     networkList.updateToggleControl('airplaneMode', data.airplaneMode);
+    networkList.endBatchUpdates();
   };
 
   /**
    * Element for indicating a policy managed network.
    * @constructor
    */
   function ManagedNetworkIndicator() {
     var el = cr.doc.createElement('div');
     el.__proto__ = ManagedNetworkIndicator.prototype;
     el.decorate();
@@ skipping 106 matching lines @@
    * Whether the Network list is disabled. Only used for display purpose.
    * @type {boolean}
    */
   cr.defineProperty(NetworkList, 'disabled', cr.PropertyKind.BOOL_ATTR);
 
   // Export
   return {
     NetworkList: NetworkList
   };
 });