Import open windows and tabs from legacy Brave

[garrettr]

Partial resolution brave/brave-browser#998. Only supports importing windows and tabs from legacy Brave, which is sufficient to support the goal of auto-migrating users from Muon to brave-core in 0.57.x.

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
  • Windows
  • macOS
  • Linux
• Verified that these changes pass automated tests (npm test brave_unit_tests && npm test brave_browser_tests) on
  • Windows
  • macOS
  • Linux
• 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

Test Plan:

1. Create a test set of open windows/tabs in Muon.
   • There should be at least 1 window with at least 1 tab
   • There should be at least 1 pinned tab.
   • You should select different tabs in each window (to verify the selected tabs are maintained across import).
2. In Muon's preferences, verify the setting "Brave starts with" is set to "My windows / tabs from last time" (the default).
3. Quit Muon.

1. Manual import

Clear the Brave Development user data directory, then:

1. npm start
2. Once browser comes up, go to chrome://settings/importData
3. In the drop down, pick Brave (old)
4. Verify a new option Open windows and tabs is present
5. Select only Open windows and tabs
6. Click Import
7. You should see the open windows and tabs open in the background (behind the window with the import dialog) and start to load.

If you select all import options, instead of only Open windows and tabs, all of the tabs should appear identical or nearly identical to what was visible when you quit Muon (because all of the session data was also imported).

2. Automatic/first-run import

Clear the Brave Development user data directory, then run the Brave binary with the --upgrade-from-muon flag, e.g. ./src/out/Debug/Brave\ Browser\ Development.app/Contents/MacOS/Brave\ Browser\ Development --enable-logging --v=0 --disable-brave-update --upgrade-from-muon.

Once loaded, this should be nearly indistinguishable from the previous Muon session. The first run experience window should remain in the foreground of all of the imported windows.

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

[darkdh]

looks good to me. can you squash three commits into one?
The patch issue is addressed in efe72e2#diff-6b0d3600d50944ab08b6145722eaa7c2

[garrettr]

@darkdh Squashed

[darkdh]

++, also did a local test and it works as expected

[garrettr]

I have tested and confirmed that this PR builds and works as expected on macOS and Linux, and I'm waiting on a Windows build so I can test there too. Once I've verified this is working on all platforms, I'll merge and request uplift to 0.57.x.

[garrettr]

Confirmed this PR builds and manual test plan passes on Windows.

[bbondy]

🎉

[bsclifton]

Great job, @garrettr! 😄 👍

[bsclifton]

master 62dbbb9
0.59.x 705ef5d
0.58.x d34758d
0.57.x f8ccd8f

[bsclifton]

Uplifted to 0.57.x 👍
cc: @kjozwiak @srirambv @rebron

[kjozwiak]

Awesome, thanks for getting this done and merged @bsclifton @garrettr 👍