MD Settings: implement "RESTART" button for hardware acceleration to take effect

chrome/browser/resources/settings/system_page/system_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 that affect how Chrome interacts with the underlying
  * operating system (i.e. network, background processes, hardware).
  */
 
 Polymer({
   is: 'settings-system-page',
 
   properties: {
-    /** @type {settings.SystemPageDelegate} */
-    delegate: {
-      type: Object,
-    },
-
     prefs: {
       type: Object,
       notify: true,
     },
   },
 
+  /**
+   * @param {boolean} enabled Whether hardware acceleration is currently
+   *     enabled.
+   * @private
+   */
+  shouldShowRestart_: function(enabled) {
+    var proxy = settings.SystemPageBrowserProxyImpl.getInstance();
+    return enabled != proxy.wasHardwareAccelerationEnabledAtStartup();
+  },
+
   /** @private */
   onChangeProxySettingsTap_: function() {
-    this.delegate.changeProxySettings();
+    settings.SystemPageBrowserProxyImpl.getInstance().changeProxySettings();
+  },
+
+  /** @private */
+  onRestartTap_: function() {
+    // TODO(dbeam): we should prompt before restarting the browser.
+    settings.SystemPageBrowserProxyImpl.getInstance().restartBrowser();
   },
 });