MD Settings: About page, implementing update status.

chrome/browser/resources/settings/about_page/about_page.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 'settings-about-page' contains version and OS related
  * information.
  */
 Polymer({
   is: 'settings-about-page',
 
-  behaviors: [RoutableBehavior],
+  behaviors: [WebUIListenerBehavior, RoutableBehavior, I18nBehavior],
 
   properties: {
     /**
      * The current active route.
      */
     currentRoute: {
       type: Object,
       notify: true,
     },
+
+    /** @private {?UpdateStatusChangedEvent} */
+    currentUpdateStatusEvent_: Object,
+
+<if expr="chromeos">
+    /**
+     * Whether the current and target channel is different.
+     * @private
+     */
+    channelsDiffer_: Boolean,
+
+    /** @private {!BrowserChannel} */
+    targetChannel_: String,
+</if>
   },
 
   /** @private {?settings.AboutPageBrowserProxy} */
   browserProxy_: null,
 
   /**
    * @type {string} Selector to get the sections.
    * TODO(michaelpg): replace duplicate docs with @override once b/24294625
    * is fixed.
    */
   sectionSelector: 'settings-section',
 
   /** @override */
   ready: function() {
     this.browserProxy_ = settings.AboutPageBrowserProxyImpl.getInstance();
+    this.browserProxy_.pageReady();
+
+<if expr="chromeos">
+    Promise.all([
+      this.browserProxy_.getCurrentChannel(),
+      this.browserProxy_.getTargetChannel(),
+    ]).then(function(channels) {
+      this.targetChannel_ = channels[1];
+      this.channelsDiffer_ = channels[0] != this.targetChannel_;
+      this.startListening_();
+    }.bind(this));
+</if>
+<if expr="not chromeos">
+    this.startListening_();
+</if>
+  },
+
+  /** @private */
+  startListening_: function() {
+    this.addWebUIListener(
+        'update-status-changed',
+        /** @param {!UpdateStatusChangedEvent} event */
+        function(event) {
+          this.currentUpdateStatusEvent_ = event;
+        }.bind(this));
+    this.browserProxy_.refreshUpdateStatus();
   },
 
    /** @override */
   attached: function() {
     this.scroller = this.parentElement;
   },
 
   /** @private */
   onHelpTap_: function() {
     this.browserProxy_.openHelpPage();
   },
 
+  /**
+   * @return {boolean}
+   * @private
+   */
+  shouldShowUpdateStatus_: function() {
+    return this.currentUpdateStatusEvent_.status != UpdateStatus.DISABLED;
+  },
+
+  /**
+   * @return {string}
+   * @private
+   */
+  getUpdateStatusMessage_: function() {
+    switch (this.currentUpdateStatusEvent_.status) {
+      case UpdateStatus.CHECKING:
+        return this.i18n('aboutUpgradeCheckStarted');
+      case UpdateStatus.NEARLY_UPDATED:
+<if expr="chromeos">
+        if (this.channelsDiffer_)
+          return this.i18n('aboutUpgradeSuccessChannelSwitch');
+</if>
+        return this.i18n('aboutUpgradeRelaunch');
+      case UpdateStatus.UPDATED:
+        return this.i18n('aboutUpgradeUpToDate');
+      case UpdateStatus.UPDATING:
+<if expr="chromeos">
+        if (this.channelsDiffer_) {
+          return this.i18n('aboutUpgradeUpdatingChannelSwitch',
+              this.i18n(settings.browserChannelToI18nId(this.targetChannel_)));
+        }
+</if>
+        return this.i18n('aboutUpgradeUpdating');
+      default:
+        return this.currentUpdateStatusEvent_.message;
+    }
+  },
+
+  /**
+   * @return {?string}
+   * @private
+   */
+  getIcon_: function() {
+    switch (this.currentUpdateStatusEvent_.status) {
+      case UpdateStatus.DISABLED_BY_ADMIN:
+        return 'cr:domain';
+      case UpdateStatus.FAILED:
+        return 'settings:error';
+      case UpdateStatus.UPDATED:
+      case UpdateStatus.NEARLY_UPDATED:
+          return 'settings:check-circle';
+      default:
+          return null;
+    }
+  },
+
+  /**
+   * @return {?string}
+   * @private
+   */
+  getIconSrc_: function() {
+    switch (this.currentUpdateStatusEvent_.status) {
+      case UpdateStatus.CHECKING:
+      case UpdateStatus.UPDATING:
+        return 'chrome://resources/images/throbber_small.svg';
+      default:
+        return null;
+    }
+  },
+
 <if expr="chromeos">
   /** @private */
   onDetailedBuildInfoTap_: function() {
     var animatedPages = /** @type {!SettingsAnimatedPagesElement} */ (
         this.$.pages);
     animatedPages.setSubpageChain(['detailed-build-info']);
   },
 </if>
 
 <if expr="_google_chrome">
   /** @private */
   onReportIssueTap_: function() {
     this.browserProxy_.openFeedbackDialog();
   },
 </if>
 });