webui: remove FocusManager.disableMouseFocusOnButtons().

chrome/browser/resources/uber/uber_frame.js

 // Copyright (c) 2012 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.
 
 // This file contains the navigation controls that are visible on the left side
 // of the uber page. It exists separately from uber.js so that it may be loaded
 // in an iframe. Iframes can be layered on top of each other, but not mixed in
 // with page content, so all overlapping content on uber must be framed.
 
 <include src="../../../../ui/webui/resources/js/util.js">
 <include src="uber_utils.js">
 
 cr.define('uber_frame', function() {
 
   /**
    * Handles page initialization.
    */
   function onLoad() {
     var navigationItems = document.querySelectorAll('li');
 
     for (var i = 0; i < navigationItems.length; ++i) {
       navigationItems[i].addEventListener('click', onNavItemClicked);
     }
 
     window.addEventListener('message', handleWindowMessage);
     uber.invokeMethodOnParent('navigationControlsLoaded');
 
     document.documentElement.addEventListener('mousewheel', onMouseWheel);
     document.documentElement.addEventListener('mousedown', onMouseDown);
-    cr.ui.FocusManager.disableMouseFocusOnButtons();
   }
 
   /**
    * Handles clicks on the navigation controls (switches the page and updates
    * the URL).
    * @param {Event} e The click event.
    */
   function onNavItemClicked(e) {
     // Though pointer-event: none; is applied to the .selected nav item, users
     // can still tab to them and press enter/space which simulates a click.
@@ skipping 135 matching lines @@
   }
 
   return {
     onLoad: onLoad,
     setNavigationOverride: setNavigationOverride,
   };
 
 });
 
 document.addEventListener('DOMContentLoaded', uber_frame.onLoad);