Onion addresses spawn new tor private window

[taperj]

Onion addresses spawn new tor private window even if a proxy that has access to tor is being used in the main window.

Steps to Reproduce

1. Set search engine to duckduckgo's .onion address and set as default search engine.
2. Search from the address bar.
3. Brave spawns new private window with Tor instead of using it's current window which is not good behavior.
4. Users having "normal" proxies that access Tor as a segment from within the "normal" proxy cannot use onion addresses anymore from the browser non-private window (ie. - using a squid proxy that is aware and has a stub to Tor from within).
5. This, in one step, has rendered the browser fairly useless for customized advanced consolidated privacy.

Actual result:

New private window with Tor is spawned

Expected result:

usage of the "normal" squid proxy configured and letting that proxy handle the dns resolutionand routing to .onion(or not).
Brave should not override and spawn a new Tor window solely based on domain extension, it should use the proxy configured.

Reproduces how often:

Happens every time.

Brave version (info found on brave://version)

Version 1.18.70 Chromium: 87.0.4280.101 (Official Build) (64-bit)

problem reproduced on windows and linux, this (bad) behavior has been introduced in the last couple releases I believe.

• Can you reproduce this issue with the current release?
  -yes

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields?
  No
• Does the issue resolve itself when disabling Brave Rewards?
  No

[diracdeltas]

does this happen if you turn off the onion redirect setting in brave://settings/?search=onion?

[taperj]

@diracdeltas Thanks for the reply!

does this happen if you turn off the onion redirect setting in brave://settings/?search=onion?

Yes, it still happens with the onion redirect setting disabled. I've toggled it on and off and it exhibits this same behavior both ways.

[diracdeltas]

^ cc @darkdh

[darkdh]

that setting is effective for onion-location header auto redirect currently, I will make .onion address redirect to check that setting too.

[LaurenWags]

Verified passed with

Brave | 1.20.87 Chromium: 88.0.4324.96 (Official Build) dev (x86_64)
-- | --
Revision | 68dba2d8a0b149a1d3afac56fa74648032bcf46b-refs/branch-heads/4324@{#1784}
OS | macOS Version 10.15.7 (Build 19H15)

Reproduced the issue using 1.19.86.
Verified test plan from brave/brave-core#7517.
Confirmed if "Automatically redirect .onion sites" is off, visiting https://brave5t5rjjg3s6k.onion/ in a normal window does not open a Tor window.
Confirmed if "Automatically redirect .onion sites" is on, visiting https://brave5t5rjjg3s6k.onion/ in a normal window does open a Tor window.

Per #13236 (comment), also confirmed the below:
Confirmed if "Automatically redirect .onion sites" is off, visiting https://brave.com/ in a normal window does not open a Tor window.
Confirmed if "Automatically redirect .onion sites" is on, visiting https://brave.com/ in a normal window does open a Tor window.

---

Verification passed on

Brave | 1.20.88 Chromium: 88.0.4324.96 (Official Build) dev (64-bit)
-- | --
Revision | 68dba2d8a0b149a1d3afac56fa74648032bcf46b-refs/branch-heads/4324@{#1784}
OS | Windows 10 OS Version 2004 (Build 19041.746)

Reproduced the issue using 1.19.86.
Verified test plan from brave/brave-core#7517.
Confirmed if "Automatically redirect .onion sites" is off, visiting https://brave5t5rjjg3s6k.onion/ in a normal window does not open a Tor window.
Confirmed if "Automatically redirect .onion sites" is on, visiting https://brave5t5rjjg3s6k.onion/ in a normal window does open a Tor window.

Per #13236 (comment), also confirmed the below:
Confirmed if "Automatically redirect .onion sites" is off, visiting https://brave.com/ in a normal window does not open a Tor window.
Confirmed if "Automatically redirect .onion sites" is on, visiting https://brave.com/ in a normal window does open a Tor window.

---

Verification passed on

Brave	1.20.88 Chromium: 88.0.4324.96 (Official Build) dev (64-bit)
Revision	68dba2d8a0b149a1d3afac56fa74648032bcf46b-refs/branch-heads/4324@{#1784}
OS	Ubuntu 18.04 LTS

Verified test plan from brave/brave-core#7517.

Verified test plan from brave/brave-core#7517.
Confirmed if "Automatically redirect .onion sites" is off, visiting https://brave5t5rjjg3s6k.onion/ in a normal window does not open a Tor window.
Confirmed if "Automatically redirect .onion sites" is on, visiting https://brave5t5rjjg3s6k.onion/ in a normal window does open a Tor window.

Per #13236 (comment), also confirmed the below:
Confirmed if "Automatically redirect .onion sites" is off, visiting https://brave.com/ in a normal window does not open a Tor window.
Confirmed if "Automatically redirect .onion sites" is on, visiting https://brave.com/ in a normal window does open a Tor window.

Encountered #13736