Fixes hover over keys changing cursor icon.

ui/keyboard/resources/main.css

 /*
  Copyright (c) 2013 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.
 */
 
 @font-face {
   font-family: roboto-bold;
   src: url(roboto_bold.ttf);
 }
 
 body {
   -webkit-user-select: none;
   background-image: -webkit-linear-gradient(#282828, #000000);
   background-size: cover;
+  cursor: default;
   margin: 0;
   overflow: hidden;
   padding: 0;
 }
 
 kb-keyboard.ctrl-active kb-modifier-key[char=Ctrl],
 kb-keyboard.alt-active kb-modifier-key[char=Alt],
 /**
 * Controls whether the shift key should be highlighted or not.
 * Only highlights if we are in the upper keyset, but not capslocked.
@@ skipping 33 matching lines @@
 
 .audio .microphone [part=key] {
   background-image: url('images/microphone-green.svg');
 }
 
 kb-key.search [part=key]{
   margin-left: 0px;
   padding-left: 0px;
   width: 2em;
 }