message: Hide browser a11y outline on context menus
  Fixes
  Regressed by
  Class introduced in
diff: @@ -167,6 +167,7 @@ export default class ContextualMenu extends React.Component {
  const menuClasses = classNames({
  'mx_ContextualMenu': true,
  + 'mx_HiddenFocusable': true, // hide browser outline
  'mx_ContextualMenu_left': !hasChevron && position.left,
  'mx_ContextualMenu_right': !hasChevron && position.right,
  'mx_ContextualMenu_top': !hasChevron && position.top,
  