[media-internals] Add note to clipboard dialog

content/browser/resources/media/media_internals.css

 /* Copyright 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. */
 
 html,
 body,
 #container {
   margin: 0;
   padding: 0;
   width: 100%;
@@ skipping 108 matching lines @@
   position: fixed;
 }
 
 #graphs li {
   list-style-type: none;
 }
 
 #clipboard-dialog {
   top: 0;
   bottom: 0;
+  padding-top: 0;
 }
 
 ::backdrop {
   background-color: #000;
   opacity: 0.5;
 }
 
 .timestamp {
   min-width: 115px;
 }
@@ skipping 60 matching lines @@
 
 .no-players-selected #players .property-wrapper,
 .no-players-selected #players #log-wrapper {
   display: none;
 }
 
 .no-components-selected #audio .property-wrapper {
   display: none;
 }