extensions: allow trash to have a focus outline.

ui/webui/resources/css/trash.css

 /* 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. */
 
 .trash {
   -webkit-appearance: none;
   background: none;
   border: none;
   cursor: pointer;
   display: inline-block;
@@ skipping 20 matching lines @@
   -webkit-transform-origin: -7% 100%;
   -webkit-transition: -webkit-transform 150ms;
   height: 6px;
   width: 14px;
 }
 
 html[dir='rtl'] .trash > .lid {
   -webkit-transform-origin: 107% 100%;
 }
 
-.trash:focus > .lid,
-.trash:hover > .lid {
+.trash:-webkit-any(:focus, :hover, .open) > .lid {
   -webkit-transform: rotate(-45deg);
   -webkit-transition: -webkit-transform 250ms;
 }
 
-html[dir='rtl'] .trash:focus > .lid,
-html[dir='rtl'] .trash:hover > .lid {
+html[dir='rtl'] .trash:-webkit-any(:focus, :hover, .open) > .lid {
   -webkit-transform: rotate(45deg);
 }
 
 .trash > .can {
   background-position: -1px -4px;
   height: 12px;
   /* The margins match the background position offsets. */
   margin-left: 1px;
   /* The right margin is one greater due to a shadow on the trash image. */
   margin-right: 2px;
   margin-top: 4px;
   width: 11px;
 }