Fixes an issue with Wordpress 4.3 doing some funky things in Chrome.

wp-admin-menu-fix.php

<?php
add_action('admin_enqueue_scripts', 'hudsonawning_chrome_fix');
/**
 * Fixes an issue with the admin menu doing funky things in Chrome.
 * It's rather annoying.
 *
 * @param none
 * @return none
 */
function hudsonawning_chrome_fix() {

  if ( strpos( $_SERVER['HTTP_USER_AGENT'], 'Chrome' ) !== false ) {
    wp_add_inline_style( 'wp-admin', '#adminmenu { transform: translateZ(0); }' );
  }

}