Sometimes no active tab is selected after closing a tab

[bbondy]

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

• Describe the issue you encountered:
  Closing a tab can sometimes lead to no active tab being set.

• Platform (Win7, 8, 10? macOS? Linux distro?):
  macOS, but probably all.

• Brave Version (revision SHA):
  0.17.7

• Steps to reproduce:

  1. Open a bunch of tabs, make a google docs spreadsheet the active one.
  2. Command+W

• Actual result:
  You may find that there's no active tab set after the tab close.
  Shift+F8 gives console error pointing to frame.get where frame is undefined in AudioTabIcon component.

• Expected result:
  Should close and select a new tab as active.

• Will the steps above reproduce in a fresh profile? If not what other info can be added?
  I don't think it's more or less likely on a new profile.

• Is this an issue in the currently released version?
  I don't think so.

• Can this issue be consistently reproduced?
  No.

[bsclifton]

Fixed with #9687