Chrome/Firefox importers should not import cookies

[fmarier]

Currently, we appear to be importing all Chrome cookies into Brave when a user chooses to import cookies (presumably the same is true for Firefox and any other browsers we import from).

To avoid importing any tracking cookies, we should:

1. avoid importing cookies that were set in a third-party context
2. impose a 6-month limit to any cookies we import (to match the limit we impose on new cookies)

I'm not sure whether there's a way to tell third-party cookies or not, but a larger question (for @tomlowenthal) is: should we import cookies at all?

Importing legitimate login cookies does reduce the friction involved in migrating to a new browser, but perhaps migrating saved passwords is good enough to reduce the pain of having to relogin.

[tildelowengrimm]

I don't think we need to import cookies. Let's just drop that.

[iefremov]

@tomlowenthal I assume we should still import cookies from Brave profiles?

[bsclifton]

Updated title, per brave/brave-core#4121 (comment)

[bsclifton]

Bumping up to P2 after recent conversations with @BrendanEich

[LaurenWags]

Verified passed with

Brave	1.1.22 Chromium: 79.0.3945.79 (Official Build) (64-bit)
Revision	29f75ce3f42b007bd80361b0dfcfee3a13ff90b8-refs/branch-heads/3945@{#916}
OS	macOS Version 10.13.6 (Build 17G5019)

• Verified importing from Firefox and Chrome via brave://welcome flow does not import cookies
  • Verified cookie DB is empty after importing from Firefox and Chrome.
  • Verified importing from Firefox via brave://welcome flow does import History and Bookmarks. Passwords, Search Engine and Autofill are not imported - see logged issue Passwords, Search Engine, and Autofill are not imported from Firefox #2198
  • Verified importing from Chrome via brave://welcome flow does import History, Bookmarks, and Passwords as expected.
• Verified importing from Firefox and Chrome via brave://settings/importData does not import cookies
  • Verified cookie DB is empty after importing from Firefox and Chrome.
  • Verified importing from Firefox via brave://settings/importData does import History and Bookmarks. Passwords, Search Engine and Autofill are not imported - see logged issue Passwords, Search Engine, and Autofill are not imported from Firefox #2198
  • Verified importing from Chrome via brave://settings/importData does import History, Bookmarks, and Passwords as expected.
  • Verified importing from Safari and Bookmarks HTML file imports Bookmarks as expected on brave://settings/importData.
• Verified there is no checkbox to import Cookies when importing from Firefox or Chrome on brave://settings/importData

• Cookies can still be imported via Brave (old), but this will be removed with Remove muon / Brave (old) from importer #7403

---

Verification passed on

Brave	1.1.22 Chromium: 79.0.3945.79 (Official Build) (64-bit)
Revision	29f75ce3f42b007bd80361b0dfcfee3a13ff90b8-refs/branch-heads/3945@{#916}
OS	Linux

• Verified importing from brave://welcome doesn't import any cookies from FF/Chrome
• Verified importing from brave://settings/importData doesn't show cookies option for Firefox
  
• Verified importing from brave://settings/importData doesn't show cookies option for Chrome
  
• Verified importing data from Firefox or Chrome manually doesn't import any cookies
• Verified setting a first-party cookie on FF/Chrome and importing data doesn't import the first party cookie to Brave
• Verified setting a third-party cookie on FF/Chrome via Google login doesn't import the cookie or session into Brave
• Verified Cookie database is empty after data is imported from FF/Chrome
• Verified import fails if FF/Chrome window is still open when trying to import browser data
• Verified passwords are successfully imported but sessions are not when importing data from Chrome
• Verified browser history is imported and shows up in URL suggestions after data is imported from FF/Chrome

Verification PASSED on Win 10 x64 using the following build:

Brave	1.1.22 Chromium: 79.0.3945.79 (Official Build) (64-bit)
Revision	29f75ce3f42b007bd80361b0dfcfee3a13ff90b8-refs/branch-heads/3945@{#916}
OS	Windows 10 OS Version 1909 (Build 18363.535)

• ensured that the To finish importing, close all Chrome windows modal is being displayed when importing via brave://welcome & brave://settings/importData while Chrome is opened
• ensured that the To finish importing, close all Firefox windows modal is being displayed when importing via brave://welcome & brave://settings/importData while Chrome is opened
• ensured that \AppData\Local\BraveSoftware\Brave-Browser\User Data\Default\Cookies was empty after importing from Chrome and Firefox
• ensured bookmarks, passwords and history are being imported without any issues on both Firefox and Chrome via brave://welcome & brave://settings/importData
• ensured that the imported passwords can be auto-filled on the appropriate websites
• ensures sessions are not being restored as the cookies are being cleared

[Srini-B]

Removing such a useful feature now made me not use this browser, it would take me a lot of time to log back in on all sites