Implement word wrapping and panning in multiline Braille.

chrome/browser/resources/chromeos/chromevox/cvox2/background/panel.css

 /* Copyright 2016 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 {
   border: 0;
   height: 35px;
   margin: 0;
   overflow: hidden;
   padding: 0;
@@ skipping 97 matching lines @@
 
 #braille-container * {
   border-spacing: 0;
   color: #fff;
 }
 
 #braille-table-holder-outer {
   display: flex;
   height: 100%;
   overflow: scroll;
-  padding-bottom: 17px;
   padding-right: 17px;
   width: 100%;
 }
 
 .braille-table-holder {
   flex-grow: 1;
 }
 
 #braille-text {
   font-family: 'Droid Sans Mono', Courier, monospace;
@@ skipping 201 matching lines @@
   border: 1px solid black;
 }
 
 /*
  * The html hidden attribute doesn't make elements not focusable by default.
  * This rule ensures that elements that are hidden truly don't show up.
  */
 *[hidden] {
   display: none !important;
 }