Extension popup menu items dismissed on click

[alexwykoff]

Test plan

1. Enable an extension which uses popup menus when clicked (bitwarden, lastpass)
2. Click the extension icon to show the popup menu
3. Click something in the popup. It should actually work (instead of dismissing without processing)
4. Using the DOM inspector, you should be able to show the popup menu and inspect. The class name should start with popupMenu

Original issue description

• Did you search for similar issues before submitting this one?
  yes

• Describe the issue you encountered:
  after enabling bitwarden, i could not log in or create an account via the URLbar menu

• Platform (Win7, 8, 10? macOS? Linux distro?):
  macOS

• Brave Version (revision SHA):
  0.18.10

• Steps to reproduce:

  1. enable bitwarden
  2. attempt to log in or create an account

• Actual result:
  nothing happens when clicking on the menu items

• Expected result:
  i should be able to log in or create an account

• Will the steps above reproduce in a fresh profile? If not what other info can be added?
  yes

• Is this an issue in the currently released version?
  no

• Can this issue be consistently reproduced?
  yes

• Extra QA steps:
  1.
  2.
  3.

• Screenshot if needed:

• Any related issues:

[bsclifton]

This should be fixed after 38f4618