Settings/Oobe: Simplify cr-network-select and use flex

chrome/browser/resources/chromeos/login/oobe_welcome.js

 // Copyright 2016 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.
 
 /**
  * @fileoverview Polymer element for displaying material design OOBE.
  */
 
 Polymer({
   is: 'oobe-welcome-md',
@@ skipping 54 matching lines @@
       type: Boolean,
       value: false,
     },
 
     /**
      * Flag that shows Network Selection screen.
      */
     networkSelectionScreenShown: {
       type: Boolean,
       value: false,
+      observer: 'networkSelectionScreenShownChanged_',
     },
 
     /**
      * Flag that enables MD-OOBE.
      */
     enabled: {
       type: Boolean,
       value: false,
     },
 
@@ skipping 41 matching lines @@
    */
   networkLastSelectedGuid_: '',
 
   /**
    * Sets proper focus.
    */
   focus: function() {
     this.$.welcomeNextButton.focus();
   },
 
+  /** @private */
+  networkSelectionScreenShownChanged_: function() {
+    if (this.networkSelectionScreenShown) {
+      // After #networkSelect is stamped, trigger a refresh so that the list
+      // will be updated with the currently visible networks and sized
+      // appropriately.
+      this.async(function() {
+        this.$.networkSelect.refreshNetworks();
+      }.bind(this));
+    }
+  },
+
   /**
    * Handles "visible" event.
    * @private
    */
   onAnimationFinish_: function() {
     this.focus();
   },
 
   /**
    * Returns custom items for network selector.
@@ skipping 263 matching lines @@
    * @private
    */
   onTimezoneSelected_: function(event) {
     var item = event.detail;
     if (!item)
       return;
 
     this.screen.onTimezoneSelected_(item.value);
   },
 });