chromeos: Add Power device page to chrome://md-settings.

chrome/browser/resources/settings/device_page/device_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-device-page' is the settings page for device and
  * peripheral settings.
  */
 Polymer({
   is: 'settings-device-page',
@@ skipping 99 matching lines @@
 
   /**
    * Handler for tapping the Display settings menu item.
    * @private
    */
   onDisplayTap_: function() {
     settings.navigateTo(settings.Route.DISPLAY);
   },
 
   /**
+   * Handler for tapping the Power settings menu item.
+   * @private
+   */
+  onPowerTap_: function() {
+    settings.navigateTo(settings.Route.POWER);
+  },
+
+  /**
    * Handler for tapping the Storage settings menu item.
    * @private
    */
   onStorageTap_: function() {
     settings.navigateTo(settings.Route.STORAGE);
   },
 
   /** @protected */
   currentRouteChanged: function() {
     this.checkPointerSubpage_();
@@ skipping 14 matching lines @@
    * @private
    */
   checkPointerSubpage_: function() {
     // Check that the properties have explicitly been set to false.
     if (this.hasMouse_ === false && this.hasTouchpad_ === false &&
         settings.getCurrentRoute() == settings.Route.POINTERS) {
       settings.navigateTo(settings.Route.DEVICE);
     }
   },
 });