Remove hard-coded font families in WebUI.

chrome/browser/resources/gesture_config.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 {
-  font-family: 'Noto Sans UI', sans-serif;
-  font-size: 12px;
-}
-
 form {
   display: table;
   margin: 8px;
 }
 
 h2 {
   border-bottom: 1px solid rgb(238, 238, 238);
   color: rgb(48, 57, 66);
 }
 
@@ skipping 57 matching lines @@
 
 .section-properties {
   border-spacing: 8px;
   display: table;
 }
 
 #section-row-template,
 #section-template {
   display: none;
 }