[MD settings] on startup use current pages

chrome/browser/resources/settings/on_startup_page/startup_urls_page.js

 // Copyright 2015 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 'cr-settings-startup-urls-page' is the settings page
  * containing the urls that will be opened when chrome is started.
  *
  * Example:
  *
@@ skipping 18 matching lines @@
       notify: true,
     },
 
     newUrl: {
       type: String,
     },
 
     /** @type {!Array<string>} */
     savedUrlList: {
       type: Array,
-      value: function() { return []; }
     },
   },
 
+  observers: [
+    'prefsChanged_(prefs.session.startup_urls.value.*)',
+  ],
+
+  attached: function() {
+    var updateFunction = this.updateStartupPages_.bind(this);
+    cr.define('Settings', function() {
+      return {
+        updateStartupPages: updateFunction,
+      };
+    });
+  },
+
+  /** @private */
+  prefsChanged_: function(change) {
+    if (this.savedUrlList == undefined &&
+        this.get('prefs.session.startup_urls')) {
+      this.savedUrlList = this.prefs.session.startup_urls.value.slice();
+    }
+  },
+
+  /** @private */
+  updateStartupPages_: function(data) {
+    var urlArray = [];
+    for (var i = 0; i < data.length; ++i)
+      urlArray.push(data[i].url);
+    this.set('prefs.session.startup_urls.value', urlArray);
+  },
+
   /** @private */
   onUseCurrentPagesTap_: function() {
-    // TODO(dschuyler): I'll be making a chrome.send call here.
+    chrome.send('setStartupPagesToCurrentPages');
   },
 
   /** @private */
   onCancelTap_: function() {
-    this.set('prefs.session.startup_urls.value', this.savedUrlList.slice());
+    if (this.savedUrlList !== undefined) {
+      this.set('prefs.session.startup_urls.value', this.savedUrlList.slice());
+    }
   },
 
   /** @private */
   onOkTap_: function() {
     var value = this.newUrl && this.newUrl.trim();
     if (!value)
       return;
     this.push('prefs.session.startup_urls.value', value);
     this.newUrl = '';
   },
 
   /**
    * @param {!{model: !{index: number}}} e
    * @private
    */
   onRemoveUrlTap_: function(e) {
     this.splice('prefs.session.startup_urls.value', e.model.index, 1);
   },
 });