Append --disable-sync swtich to disable sync temporarily

[darkdh]

fix brave/brave-browser#8141

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. Enable sync with older version
2. Relaunch sync with this fix
3. Go to about://version, there should be a --disable-sync switch
4. Check sync item in menu is inaccessible
5. Go to brave://sync/, it will show This site can’t be reached

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.

[AlexeyBarabash]

++

[darkdh]

The only failure is network audit
https://ci.brave.com/job/brave-browser-build-pr/job/disable-sync-temp/3/execution/node/532/log/

[kjozwiak]

Thanks to @srirambv (@GeetaSarvadnya helped as well) for creating the following cases that QA also went through to ensure that disabling sync didn't cause any issues:

Sync enabled on previous version

• Enable sync on 1.2.42 and add a desktop to the sync chain
• Have bookmarks imported on device B to have them sync'd on device A
• Add a bookmark on device A
• Manually add the same bookmark on device A to make it duplicate
• Quit browser on device B while sync is in progress
• Upgrade device A to 1.3.115
• Ensure sync is diabled and not shown in hamburger menu and no bookmarks that are sync'd are lost
• Visiting brave://sync shows invalid page error
• Ensure no sync is happening on device B and none of the bookmarks from device A are sent

Sync not enabled on previous version

• Install 1.2.43
• Ensure Sync option is shown in hamburger menu
• Visit brave://sync, ensure sync start page is shown
• Upgrade to 1.3.115
• Ensure no sync option in hamburger menu
• Visit brave://sync, shows invalid page error

Clean install

• Clean install 1.3.115
• Ensure no sync option in hambuger menu
• Visit brave://sync, shows invalid page error

Crash profile

• Install 1.2.43 and enable sync
• Replace the crash bookmarks in profile
• Upgrade to 1.3.113
• Ensure browser goes into crash mode
• Upgrade to 1.3.115
• Ensure browser doesn't crash after launch
• Ensure sync is disabled in hamburger menu and no bookmarks are lost

Component Extension

• Install 1.2.43 and enable sync
• Check Brave Sync component is listed in brave://extensions
• Upgrade to 1.3.115
• Check Brave sync component is not listed in brave://extensions

Sync disable in all tabs

• open brave://sync or click on sync in hamburger menu in NT, sync should be disabled
• open brave://sync or click on sync in hamburger menu in PT, sync should be disabled
• open brave://sync or click on sync in hamburger menu in TOR tab, sync should be disabled
• check console logs

Multiple profile

• Open multiple profiles from Create a new profile and make sure sync is disabled in all created profile

Check process in task manager

• In each case Extension: Brave Sync process should not be listed in the task manger