Remove extra spacing in clear browsing data dialog for PT/Tor windows

[AlexNguyen1612]

This removed the extra space at the top of the clear browsing data dialog (for Private/Tor windows) that the (removed) header art left so that the UI looks more symmetrical for users

Fix brave/brave-browser#21771

Here are some screenshots

Final version

Resolves

Submitter Checklist:

• I confirm that no security/privacy review is needed, or that I have requested one
• There is a ticket for my issue
• Used Github auto-closing keywords in the PR description above
• Wrote a good PR/commit description
• Squashed any review feedback or "fixup" commits before merge, so that history is a record of what happened in the repo, not your PR
• Added appropriate labels (QA/Yes or QA/No; release-notes/include or release-notes/exclude; OS/...) to the associated issue
• Checked the PR locally: npm run test -- brave_browser_tests, npm run test -- brave_unit_tests, npm run lint, npm run gn_check, npm run tslint
• Ran git rebase master (if needed)

Reviewer Checklist:

• A security review is not needed, or a link to one is included in the PR description
• New files have MPL-2.0 license header
• Adequate test coverage exists to prevent regressions
• Major classes, functions and non-trivial code blocks are well-commented
• Changes in component dependencies are properly reflected in gn
• Code follows the style guide
• Test plan is specified in PR before merging

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, 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-Protections
  • 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-Exceptions-in-Brave
  • https://github.com/brave/brave-browser/wiki/QA-Guide
  • https://github.com/brave/brave-browser/wiki/P3A

Test Plan:

See steps in brave/brave-browser#21771

[bsclifton]

@AlexNguyen1612 please let us know when this is ready for review 😄

[AlexNguyen1612]

Omg, feel like I'm so bad at Git, apologies if you received notifications constantly @bsclifton (and potentially other people who followed this PR...)
This is the first time I work with fork and these kind of open-source stuff so I'm trying to get used to it 😢

[AlexNguyen1612]

Thanks to @sangwoo108 help, the fix is way easier than I originally thought, I just need to remove the "X" by adding SetShowCloseButton to the new BraveIncognitoDialog ctor
However, IMO, I think the top of the dialog looks a bit chopped off, maybe it needs bit of additional margin there? 🤔
Let me know if this looks okay to you guys @bsclifton @fallaciousreasoning

[fallaciousreasoning]

Thanks for putting this together @AlexNguyen1612! I've checked it out locally and it works well. Personally I think it looks much better the way it is now than before.

One thing, would you mind running npm run format and committing any formatting changes it makes? After that I'll kick of a build, and if it passes, request a chromium_src reviewer to have a look 😄

[AlexNguyen1612]

@fallaciousreasoning no worries, I have just committed the format changes, please have a look 😄

[sangwoo108]

Thank you for the PR!

[fallaciousreasoning]

@brave/chromium-src-reviewers, could you PTAL?

[sangwoo108]

CI passed : #14614

[AlexNguyen1612]

Not really sure what the process is but is there anything else you guys need on my end? 🤔 Just checkin
@sangwoo108 @fallaciousreasoning

[sangwoo108]

When we touch chromium_src/ files, we need approval from chromiu_src reviewers. Let me ping them.

[AlexNguyen1612]

Yayy, my very first contribution to an open source project on github!
Thanks all, especially @sangwoo108 for guiding and explaining things in details for me 🙏

Any suggestions on where to go from here? I would love to get involved and contribute more to Brave 😄
Also, how can I join the community here (on Slack)? 🤔

[sangwoo108]

Huge congratulations @AlexNguyen1612 🥳! Welcome to the world of open source!

As you did, you can pick up one of good first bug issues. If you're more ambitious than that, I think you can try scanning tasks with p4 or p5. They're worth doing, but we couldn't put effort into them due to limited resource. As for 'community', let me check that again.

[bsclifton]

Congrats @AlexNguyen1612! Great job working with the team on this one and minimizing the changes needed 😄

Added missing milestone 👍

[fallaciousreasoning]

Nice one @AlexNguyen1612! Thanks for the contribution 😄