Blank page for magnet links on clean install

[btlechowski]

magnet protocol is handled by WebTorrent extension. Magnet link is not opened on first page load on clean profile.

Important: This is a regression in 1.2.x
Note: this issue is very similar to #6472

Steps to Reproduce

1. Clean profile
2. Open https://webtorrent.io/free-torrents
3. Click a magnet link

Note: the issue is fixed after page reload
Note: not reproducible for torrent files.

Actual result:

Empty page

Expected result:

Webtorrent extension view for that magnet link

Reproduces how often:

Easily reproduced

Brave version (brave://version info)

Reproducible on

Brave	1.2.8 Chromium: 78.0.3904.108 (Official Build) dev (64-bit)
Revision	4b26898a39ee037623a72fcfb77279fce0e7d648-refs/branch-heads/3904@{#889}
OS	Ubuntu 18.04 LTS

Not reproducible on

Brave	1.0.1 Chromium: 78.0.3904.108 (Official Build) (64-bit)
Revision	4b26898a39ee037623a72fcfb77279fce0e7d648-refs/branch-heads/3904@{#889}
OS	Ubuntu 18.04 LTS

Brave	1.1.7 Chromium: 78.0.3904.108 (Official Build) beta (64-bit)
Revision	4b26898a39ee037623a72fcfb77279fce0e7d648-refs/branch-heads/3904@{#889}
OS	Ubuntu 18.04 LTS

Version/Channel Information:

• Can you reproduce this issue with the current release? no
• Can you reproduce this issue with the beta channel? no
• Can you reproduce this issue with the dev channel? yes
• Can you reproduce this issue with the nightly channel?

cc @brave/legacy_qa @feross @tomlowenthal @AndriusA

[GeetaSarvadnya]

Reproduced in windows

Brave	1.2.10 Chromium: 78.0.3904.108 (Official Build) dev (64-bit)
Revision	4b26898a39ee037623a72fcfb77279fce0e7d648-refs/branch-heads/3904@{#889}
OS	Windows 10 OS Version 1803 (Build 17134.1006)

[rebron]

cc: @yrliou Can you take a look?

[LaurenWags]

Reproduced on macOS

Brave	1.2.23 Chromium: 79.0.3945.70 (Official Build) beta (64-bit)
Revision	65868db27916cebde51fc2465c9b34761e6383e2-refs/branch-heads/3945@{#869}
OS	macOS Version 10.13.6 (Build 17G5019)

[btlechowski]

Still reproducible

Brave	1.13.77 Chromium: 85.0.4183.69 (Official Build) dev (64-bit)
Revision	4554ea1a1171bd8d06951a4b7d9336afe6c59967-refs/branch-heads/4183@{#1426}
OS	Ubuntu 18.04 LTS

[fallaciousreasoning]

Should be fixed by brave/brave-core#14568