Unsupported command line flag --save-page-as-mhtml - Save as MHTML

Description of the issue:
Chrome changed how to enable feature save as MHTML, usually it was here chrome://flags/#save-page-as-mhtml
but now, according to this, we should start browser with --save-page-as-mhtml after app name.

Steps to Reproduce (add as many as necessary): 1. 2. 3.
Write command brave-browser --save-page-as-mhtml & run

Actual Result (gifs and screenshots are welcome!):
We cannot save as MHTML as before.

Expected result:
Right click to page -> Save as… should give us option Save as MHTML.

Reproduces how often:
Always.

Operating System and Brave Version(See the About Brave page in the main menu):
Ubuntu 16.04
Brave 0.66.99 Chromium: 75.0.3770.100
Additional Information:
man brave-browser should inform about --save-page-as-mhtml but it is not there.

Hope it will help you to make your browser better. :slight_smile: