Support multi-line braille in the virtual braille display.

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

Index: chrome/browser/resources/chromeos/chromevox/chromevox/background/prefs.js
diff --git a/chrome/browser/resources/chromeos/chromevox/chromevox/background/prefs.js b/chrome/browser/resources/chromeos/chromevox/chromevox/background/prefs.js
index 34ff72bf5f3f6097f840e2903dc23d76ab8aa9d8..396a11ec2123fedd67250c42085b8dcc62e6d184 100644
--- a/chrome/browser/resources/chromeos/chromevox/chromevox/background/prefs.js
+++ b/chrome/browser/resources/chromeos/chromevox/chromevox/background/prefs.js
@@ -61,6 +61,7 @@ cvox.ChromeVoxPrefs = function() {
 cvox.ChromeVoxPrefs.DEFAULT_PREFS = {
   'active': true,
   'brailleCaptions': false,
+  'brailleSideBySide': true,
   // TODO(dtseng): Leaking state about multiple key maps here until we have a
   // class to manage multiple key maps. Also, this doesn't belong as a pref;
   // should just store in local storage.
@@ -70,6 +71,7 @@ cvox.ChromeVoxPrefs.DEFAULT_PREFS = {
   'focusFollowsMouse': false,
   'granularity': undefined,
   'position': '{}',
+  'siteSpecificEnhancements': true,
   'siteSpecificScriptBase':
       'https://ssl.gstatic.com/accessibility/javascript/ext/',
   'siteSpecificScriptLoader':
@@ -77,9 +79,10 @@ cvox.ChromeVoxPrefs.DEFAULT_PREFS = {
   'sticky': false,
   'typingEcho': 0,
   'useIBeamCursor': cvox.ChromeVox.isMac,
+  'useNext': true,
   'useVerboseMode': true,
-  'siteSpecificEnhancements': true,
-  'useNext': true
+  'virtualBrailleRows': 1,
+  'virtualBrailleColumns': 40
 };