Disable flaky test "EditingTest.RichTextMoveByLine"

chrome/browser/resources/chromeos/chromevox/cvox2/background/editing_test.extjs

 // 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.
 
 // Include test fixture.
 GEN_INCLUDE(['../../testing/chromevox_next_e2e_test_base.js',
              '../../testing/assert_additions.js']);
 
 GEN_INCLUDE(['../../testing/mock_feedback.js']);
 
@@ skipping 194 matching lines @@
     */},
     [
       {start: 0, end: 4, text: 'this'},
       {start: 5, end: 5, text: ''},
       {start: 6, end: 6, text: ''},
       {start: 7, end: 8, text: 'I'},
       {start: 9, end: 17, text: 'can test'},
     ]);
 });
 
-TEST_F('EditingTest', 'RichTextMoveByLine', function() {
+// Fails flakily, see https://crbug.com/724847.
+TEST_F('EditingTest', 'DISABLED_RichTextMoveByLine', function() {
   editing.useRichText = true;
   var mockFeedback = this.createMockFeedback();
   this.runWithLoadedTree(function() {/*!
     <div id="go" role="textbox" contenteditable>
       <h2>hello</h2>
       <div><br></div>
       <p>This is a <a href="#test">test</a> of rich text</p>
     </div>
     <script>
       var dir = 'forward';
@@ skipping 24 matching lines @@
         .expectBraille('This is a test lnk of rich text')
         .call(moveByLine)
         .expectSpeech('blank')
         .expectBraille('')
         .call(moveByLine)
         .expectSpeech('hello', 'Heading 2')
         .expectBraille('hello h2')
         .replay();
   });
 });