Make cr.ui.Focus* play nice with Shadow DOM and MD chrome://downloads

chrome/browser/resources/md_downloads/toolbar.css

 /* 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. */
 
 :host {
   @apply(--downloads-shared-style);
   align-items: center;
   background: rgb(63, 85, 102);
   color: white;
   content-sizing: padding-box;
@@ skipping 18 matching lines @@
 #actions {
   display: flex;
   flex: none;
   width: var(--downloads-item-width);
 }
 
 :host(:not([downloads-showing])) #actions {
   justify-content: center;
 }
 
-#actions cr-button {
+#actions paper-button {
   -webkit-margin-end: 8px;
 }
 
 #actions,
 #search-term {
   color: rgb(192, 199, 205);
 }
 
 #search {
   -webkit-padding-end: 10px;
@@ skipping 80 matching lines @@
     display: none;
   }
 }
 
 @media all and (max-width: 1024px) {
   /* Hide #actions for narrow windows; they're shown in a vertical dot menu. */
   #actions {
     display: none;
   }
 }