Import cookies from Chrome

[garrettr]

Support importing cookies from Chrome, per brave/brave-browser#47.

I tried to strike a balance of minimizing Chromium patches while avoiding copy-pasting large chunks of Chromium code, which is what the Muon implementation does to keep patching to an absolute minimum. As a reviewer, if you see any places where patching could be reduced without sacrificing maintainability, please let me know!

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).
• 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.

Test Plan:

Automated testing

1. yarn test brave_unit_tests
   • Output should contain ChromeImporterTest.ImportCookies and SUCCESS: all tests passed.

Manual testing

1. You will need a Chrome profile with some cookies saved in it. I have been using a test profile where I log in to an account on a specific website, e.g. https://asana.com, so the auth cookies will be saved in the Chrome profile.
2. Use a clean Brave profile: rm -rf ~/Library/Application\ Support/Brave-Development/
3. yarn start
4. In Brave, navigate to your test website, e.g. https://asana.com. You should not be logged in, because you haven't imported any cookies yet.
5. Open the main menu (e.g. Brave on macOS) and choose Import Bookmarks and Settings...
6. Choose your test Chrome profile from the dropdown menu of browser profiles.
7. Make sure the Cookies checkbox is activated.
8. Click Import.
9. Depending on your platform, you may be prompted several times to unlock keychain entries Chrome Safe Storage or Brave Safe Storage. If you are, enter your password and click Allow or Always allow.
10. Click Done to close the import dialog.
11. Refresh the page in your original tab (e.g. https://asana.com). You should be logged in.

Cross-platform testing

I will verify that this PR builds and passes both manual and automated tests on our 3 target platforms: macOS, Windows, and Linux, updating the table below as I go.

	Builds	Manual Tests Pass	Automated Tests Pass
macOS	✅	✅	✅
Windows	✅	✅	❌
Linux	✅	✅	❌

Reviewer Checklist:

• New files have MPL-2.0 license header.
• Request a security/privacy review as needed.
• Adequate test coverage exists to prevent regressions

[garrettr]

Google Chrome 66.0.3359.117 just came out today, and it updated the Cookies sqlite db schema in a backwards-incompatible manner. This PR should still work as long as you test importing from a version of Chrome < 66 (I did all of my testing with 65.0.3325.181). I'm working on a fix for the new database schema now and will push a commit to this PR once it's ready.

[darkdh]

probably caused by https://chromium.googlesource.com/chromium/src/+/23f4922cd6206fab60dd7fee798ed325ab982171
which upgraded it to version 10

[garrettr]

Updated PR to handle importing from Chrome cookie db v10.

Note that the PR now only supports importing from a v10 database, used in Chromium 66 and later. I could add support for earlier db versions, but I don't think it's worthwhile because Chrome will only be supporting v10 and above starting with C66 (released today), so by the time brave-browser sees wide release I think it's fair to assume most users who are migrating from Chrome will have upgraded to Chrome >= 66.

[darkdh]

++ 👍