Autocomplete pulldown with down arrow key

[luixxiul]

Describe the issue you encountered: It is possible to choose my log in username from the autocomplete pulldown list with the mouse, but it also should be with the down arrow key.

Expected behavior:

• Platform (Win7, 8, 10? macOS? Linux distro?): OS X
• Brave Version: https://github.com/brave/browser-laptop/tree/611f61707bfdf6087c62c965db48339d55454a74
• Steps to reproduce:
  1. Go to https://twitter.com
  2. Log out
  3. Select "Log in" from the top right link
• Screenshot if needed:
• Any related issues: Autocomplete suggestion remains #2532

[luixxiul]

cc: @darkdh

[luixxiul]

I mean this case if it's not clear:

I would like to choose the username when I push the down arrow key there.

[darkdh]

duplicate #1302