allowing users to save .torrent files via Save Link As - Follow up to #1436

[kjozwiak]

Description

Currently the only way to save a .torrent file is by clicking on the download link, which will open a new tab and load webtorrent where you can click on Save Torrent File, which is annoying. Users should have the ability to download the .torrent file via the context menu without needed to go through webtorrent.

There's currently no way of disabling webtorrent either so it's currently a pain if you're using another application for torrents.

Steps to Reproduce

1. open https://webtorrent.io/ in a new tab
2. right click on sintel.torrent and select Save Link As..

Actual result:

You'll notice that instead of download the .torrent file, brave downloads the HTML Text link.

Expected result:

Should be able to download the .torrent file via Save Link As.. as other browsers.

Reproduces how often:

100% reproducible using the above STR.

Brave version (chrome://version info)

Brave	0.69.125 Chromium: 76.0.3809.132 (Official Build) (64-bit)
Revision	fd1acc410994a7a68ac25bc77513d443f3130860-refs/branch-heads/3809@{#1035}
OS	Mac OS X

Reproducible on current release:

• Does it reproduce on brave-browser dev/beta builds? Yes
• Does it reproduce on browser-laptop? N/A

[kjozwiak]

CCing @feross. Created new issue as per #1436 (comment). Above was still broken under 0.69.x as per #1436 (comment).

[btlechowski]

Reproduced on

Brave	0.69.127 Chromium: 77.0.3865.75 (Official Build) (64-bit)
Revision	201e747d032611c5f2785cae06e894cf85be7f8a-refs/branch-heads/3865@{#776}
OS	Ubuntu 18.04 LTS

[feross]

There's currently no way of disabling webtorrent either so it's currently a pain if you're using another application for torrents.

This hasn't been true for a long time ;)

But the rest of the issue report looks good.