Fixes Tor avatar menu after c78 bump.

[mkarolin]

Also, removed no longer used override in chromium_src's profiles_state.cc.

Fixes brave/brave-browser#6451

Submitter Checklist:

• Submitted a ticket for my issue if one did not already exist.
• Used Github auto-closing keywords in the commit message.
• Added/updated tests for this change (for new code or code which already has tests).
• Verified that these changes build without errors on
  • Android
  • iOS
  • Linux
  • macOS
  • Windows
• Verified that these changes pass automated tests (unit, browser, security tests) on
  • iOS
  • Linux
  • macOS
  • Windows
• Verified that all lint errors/warnings are resolved (npm run lint)
• Ran git rebase master (if needed).
• Ran git rebase -i to squash commits (if needed).
• Tagged reviewers and labelled the pull request as needed.
• Request a security/privacy review as needed.
• Add appropriate QA labels (QA/Yes or QA/No) to include the closed issue in milestone
• Public documentation has been updated as necessary. For instance:
  • https://github.com/brave/brave-browser/wiki/Deviations-from-Chromium-(features-we-disable-or-remove)
  • https://github.com/brave/brave-browser/wiki/Proxy-redirected-URLs
  • https://github.com/brave/brave-browser/wiki/Fingerprinting-Protection-Mode
  • https://github.com/brave/brave-browser/wiki/Brave%E2%80%99s-Use-of-Referral-Codes
  • https://github.com/brave/brave-browser/wiki/Custom-Headers
  • https://github.com/brave/brave-browser/wiki/Web-compatibility-issues-with-tracking-protection
  • https://github.com/brave/brave-browser/wiki/QA-Guide

Test Plan:

1. Start Brave.
2. Open Tor window.
3. Verify that the avatar button in Tor window only has Tor icon.
4. Click on the avatar button.
5. Verify that the menu contains Tor and Exit Tor options.

Reviewer Checklist:

• New files have MPL-2.0 license header.
• Request a security/privacy review as needed.
• Adequate test coverage exists to prevent regressions
• Verify test plan is specified in PR before merging to source

After-merge Checklist:

• The associated issue milestone is set to the smallest version that the
  changes has landed on.
• All relevant documentation has been updated.

[bsclifton]

Seeing an issue with this one on Private windows; it'll always show Tor in the profile menu with this change:

Tor properly shows only Tor profile:

[mkarolin]

@bsclifton, yep, I might have skipped a return 🤣

[mkarolin]

Only lint and unrelated browser test failed in CI.

[bsclifton]

Changes work great 😄

While testing this, I noticed a weird regression - cc: @yrliou who has done Tor work in Nightly (it may be due to that work? or Chromium 78? not sure)

Basically, in Dev channel for example (C77), when in a private window with Tor, you're not given the option to create a regular private window

• via the hamburger menu
  
• via the menu (macOS)
  

On master/Nightly, when in a private window with Tor, you're shown the option to open a new private window. If you do choose this, it opens a private window with Tor, NOT a regular private window.

• hamburger menu
  
• via the menu (macOS)
  

@yrliou is this related to the work you did? Either way, I think I'll create an issue 😄

[bsclifton]

Changed LGTM! Created brave/brave-browser#6467 to track the unrelated issue I found