Fix ChromeVox Closure checks

TBR=dmazzoni@chromium.org

Change-Id: I7308081ae5c108f8865d1af360ffe21bdf6b538c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1885970Reviewed-by: David Tseng <dtseng@chromium.org>
Commit-Queue: David Tseng <dtseng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#710229}

chrome/browser/resources/chromeos/chromevox/chromevox/background/options.js

@@ -17,6 +17,7 @@ goog.require('PanelCommand');
 goog.require('cvox.BrailleTable');
 goog.require('cvox.BrailleTranslatorManager');
 goog.require('cvox.ChromeVox');
+goog.require('cvox.ChromeVoxKbHandler');
 goog.require('cvox.ChromeVoxPrefs');
 goog.require('cvox.CommandStore');
 goog.require('cvox.ExtensionBridge');

chrome/browser/resources/chromeos/chromevox/common/chromevox.js

@@ -65,10 +65,6 @@ cvox.ChromeVox.tts;
  * @type {cvox.BrailleInterface}
  */
 cvox.ChromeVox.braille;
-/**
- * @type {cvox.MathJaxInterface}
- */
-cvox.ChromeVox.mathJax;
 /**
  * @type {boolean}
  */