WebTorrent not loading due to "Unchecked runtime.lastError: Could not establish connection" error

[kjozwiak]

Description

Looks like WebTorrent has regressed in Nightly. Whenever clicking on a .torrent or .magnet link, you'll get a blank page with the following error in the browser console:

Unchecked runtime.lastError: Could not establish connection. Receiving end does not exist.
brave_webtorrent.html:1 

Steps to Reproduce

Case 1

1. install the latest Nightly (1.17.40 CR: 86.0.4240.99 in this case)
2. attempt to use WebTorrent by clicking on .torrent or .magnet links via https://webtorrent.io/free-torrents

Case 2

1. install the latest Nightly (1.17.40 CR: 86.0.4240.99 in this case)
2. attempt to load https://releases.ubuntu.com/20.04/ubuntu-20.04.1-desktop-amd64.iso.torrent

Actual result:

Expected result:

Reproduces how often:

100% reproducible using the above STR.

Brave version (brave://version info)

Brave | 1.17.40 Chromium: 86.0.4240.99 (Official Build) nightly (x86_64)
-- | --
Revision | 002668237e13d38aabd6d11c2d216dd22b736ff2-refs/branch-heads/4240@{#1229}
OS | macOS Version 10.15.7 (Build 19H2)

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 nightly channel? Yes

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields? N/A
• Does the issue resolve itself when disabling Brave Rewards? N/A
• Is the issue reproducible on the latest version of Chrome? N/A

Miscellaneous Information:

CCing @rebron @bsclifton @feross @brave/legacy_qa

[btlechowski]

Reproduced on

Brave	1.17.40 Chromium: 86.0.4240.99 (Official Build) nightly (64-bit)
Revision	002668237e13d38aabd6d11c2d216dd22b736ff2-refs/branch-heads/4240@{#1229}
OS	Windows 7 Service Pack 1 (Build 7601.24544)

Brave	1.17.40 Chromium: 86.0.4240.99 (Official Build) nightly (64-bit)
Revision	002668237e13d38aabd6d11c2d216dd22b736ff2-refs/branch-heads/4240@{#1229}
OS	Ubuntu 18.04

[kjozwiak]

Verification PASSED on macOS 10.15.7 x64 using the following build:

Brave | 1.17.42 Chromium: 86.0.4240.99 (Official Build) nightly (x86_64)
-- | --
Revision | 002668237e13d38aabd6d11c2d216dd22b736ff2-refs/branch-heads/4240@{#1229}
OS | macOS Version 10.15.7 (Build 19H2)

• Verified the STR/Cases outlined via WebTorrent not loading due to "Unchecked runtime.lastError: Could not establish connection" error #12196 (comment)
• ensured that both .torrent & .magnet links worked without issues
• ensured that Save All Files.. worked without any issues

.torrent	.magnet

---

Verification passed on

Brave | 1.17.42 Chromium: 86.0.4240.99 (Official Build) nightly (64-bit)
-- | --
Revision | 002668237e13d38aabd6d11c2d216dd22b736ff2-refs/branch-heads/4240@{#1229}
OS | Windows 10 OS Version 1903 (Build 18362.1082)

• Reproduced the issue in Nightly build 1.17.40
• Verified the STR 1 and STR 2 from the description
• ensured that both .torrent & .magnet links worked without issues
• ensured that Save All Files.. worked without any issues

.torrent	.magnet

---

Verification passed on

Brave	1.17.43 Chromium: 86.0.4240.99 (Official Build) nightly (64-bit)
Revision	002668237e13d38aabd6d11c2d216dd22b736ff2-refs/branch-heads/4240@{#1229}
OS	Ubuntu 18.04 LTS

• Verified the STR 1 and STR 2 from the description
• ensured that both .torrent & .magnet links worked without issues
• ensured that Save All Files.. worked without any issues