Clean up terminology used in about_flags.

components/flags_ui/resources/flags.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. */
 
 body {
   margin: 10px 10px 0;
 <if expr="not is_android and not is_ios">
   min-width: 47em;
 </if>
   /* Should be larger than the evaluated height of needs-restart. */
@@ skipping 125 matching lines @@
 }
 
 .experiment-name {
   font-weight: bold;
 }
 
 .referenced .experiment-name {
   background-color: rgb(255, 255, 0);
 }
 
-.no-experiments {
-  font-size: 1.2em;
-  margin: 6em 0;
-  text-align: center;
-}
-
 /* Match the indentation of .experiment-text. */
 .experiment-actions {
   -webkit-padding-start: 5px;
   margin-bottom: 0.2em;
   margin-top: 0.2em;
 }
 
 div.needs-restart {
   /* If you modify properties that change the height of this,
    * update body.padding-bottom. */
@@ skipping 23 matching lines @@
   margin-top: 10px;
   padding: 10px 24px;
   text-transform: uppercase;
   transition: box-shadow 200ms cubic-bezier(0.4, 0, 0.2, 1);
 }
 
 button {
   font-size: 104%;
 }