[Brave News]: Don't use TestingProfile in component unittests

[fallaciousreasoning]

Resolves brave/brave-browser#41534

Waiting on #25911 to merge first merged!

Submitter Checklist:

• I confirm that no security/privacy review is needed and no other type of reviews are needed, or that I have requested them
• 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 wiki
  • npm run presubmit wiki, 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/Web-Compatibility-Exceptions-in-Brave
  • https://github.com/brave/brave-browser/wiki/QA-Guide
  • https://github.com/brave/brave-browser/wiki/P3A

Test Plan:

N/A

[fallaciousreasoning]

Note: This needs to merge AFTER #25911

[simonhong]

++
optional: imo, test/BUILD.gn should be in same directory with test files.

[github-actions]

[puLL-Merge] - brave/brave-core@25914

Description

This PR refactors the test setup for Brave News components, removing dependencies on Chrome-specific testing infrastructure and replacing them with more focused, component-specific test utilities. The changes aim to improve the modularity and independence of the Brave News tests.

Changes

Changes

1. components/brave_news/browser/DEPS:

   • Removed specific include rules for unit tests, simplifying the dependencies.

2. components/brave_news/browser/brave_news_pref_manager_unittest.cc:

   • Replaced TestingProfile with sync_preferences::TestingPrefServiceSyncable.
   • Updated test setup to use a standalone PrefService instead of relying on a full Profile.

3. components/brave_news/browser/channels_controller_unittest.cc:

   • Similar changes as in brave_news_pref_manager_unittest.cc.
   • Replaced Profile-based preference management with direct PrefService usage.

4. components/brave_news/browser/direct_feed_controller_unittest.cc:

   • Removed TestingProfile dependency.
   • Simplified test setup by removing unnecessary Profile-related code.

5. components/brave_news/browser/feed_building_unittest.cc:

   • Replaced TestingProfile with sync_preferences::TestingPrefServiceSyncable.
   • Updated test setup to use standalone PrefService.

6. components/brave_news/browser/initialization_promise_unittest.cc:

   • Similar changes as in other test files, replacing Profile-based setup with PrefService-based setup.

7. components/brave_news/browser/publishers_controller_unittest.cc:

   • Replaced TestingProfile with sync_preferences::TestingPrefServiceSyncable.
   • Updated test setup to use standalone PrefService and BraveNewsPrefManager.

8. components/brave_news/browser/suggestions_controller_unittest.cc:

   • Similar changes as in other test files, replacing Profile-based setup with PrefService-based setup.

9. components/brave_news/browser/test/BUILD.gn:

   • Updated dependencies to remove Chrome-specific test support.
   • Added more focused dependencies for testing components like prefs, sync_preferences, and network.

These changes collectively move the test infrastructure away from Chrome-specific components and towards more modular, component-specific testing utilities. This should make the tests more focused and easier to maintain, as well as reducing dependencies on Chrome internals.

[fallaciousreasoning]

@simonhong agreed, but I'd rather do it as a separate PR if that's okay

[bridiver]

++ optional: imo, test/BUILD.gn should be in same directory with test files.

Huh, that is a bit weird. It could go either way, move the tests into the test directory or move the test target out of it, but follow up is fine

[brave-builds]

Released in v1.73.14