MD Settings: preload Roboto bold to reduce flicker

chrome/browser/resources/settings/settings_ui/settings_ui.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
  * 'settings-ui' implements the UI for the Settings page.
  *
  * Example:
  *
@@ skipping 87 matching lines @@
         },
         passwordsAndForms: false,
         downloads: {
           googleDrive: false,
         },
 </if>
       };
     }
   },
 
+  /** @override */
+  attached: function() {
+    // Preload bold Roboto so it doesn't load and flicker the first time used.
+    document.fonts.load('bold 12px Roboto');
+  },
+
   /**
    * @param {Event} event
    * @private
    */
   onIronActivate_: function(event) {
     if (event.detail.item.id != 'advancedPage')
       this.$$('app-drawer').close();
   },
 
   /** @private */
   onMenuButtonTap_: function() {
     this.$$('app-drawer').toggle();
   },
 
   /** @private */
   directionDelegateChanged_: function() {
     this.$$('app-drawer').align = this.directionDelegate.isRtl() ?
         'right' : 'left';
   },
 });