Toolbar and UI elements scale setting change is applied before restarting

[luixxiul]

Describe the issue you encountered: Toolbar and UI elements scale setting change is applied before restarting.

Brave: 0.18.22
rev: d850e28
Muon: 4.3.9
libchromiumcontent: 60.0.3112.90
V8: 6.0.286.52
Node.js: 7.9.0
Update Channel: dev
OS Platform: Linux
OS Release: 4.9.0-3-amd64
OS Architecture: x64

It is reproduced on Windows 10 as well.

• Steps to reproduce:

  1. Open about:preferences#advanced
  2. Change Toolbar and UI elements scale settings

• Actual result: See above

• Expected result: the change should be applied either a) instantly without the notification bar or b) after restart with the notification bar

• Extra QA steps:
  1.
  2.
  3.

• Any related issues: not prompted to restart Brave when changing preferences marked with an asterisk #10410

[bsclifton]

Closing as a duplicate of #10089