Deleting a browser profile should not delete that data from Synced profiles

[Brave-Matt]

Description

In Brave, deleting a browser profile deletes all associated data with that profile. It also deletes all that same data from any devices that are on a Sync chain with that device — the same way it would if you were only deleting the data not the profile.

As @AlexeyBarabash points out, Chromium has code to prevent this propagation of data:

// Disables sync in order to prevent that browsing data deletions propagate
// across devices via sync.
void DisableSyncForProfileDeletion(Profile* profile) {
  signin::IdentityManager* identity_manager =
      IdentityManagerFactory::GetForProfileIfExists(profile);
  if (!identity_manager ||
      !identity_manager->HasPrimaryAccount(signin::ConsentLevel::kSignin)) {
    // Nothing to do as the user is signed out (hence sync is guaranteed to be
    // disabled).
    return;
  }

Brave also needs this same protection to ensure users do not unintentionally delete their browsing data across devices when trying to delete a profile.

Steps to reproduce

1. Have 2+ browser profiles on the same chain
2. Delete a browser profile
3. Observe any shared data also gets deleted from Synced devices

Actual result

Data deleted from Synced devices

Expected result

Data on other devices should be preserved unless the data is explicitly deleted by the user.

Reproduces how often

Easily reproduced

Brave version (brave://version info)

v1.67.123

Channel information

• [X] release (stable)
• [X] beta
• [X] nightly

Reproducibility

• [ ] with Brave Shields disabled
• [ ] with Brave Rewards disabled
• [ ] in the latest version of Chrome

Miscellaneous information

User reports: https://community.brave.com/t/lost-sync-data-i-still-have-the-sync-code/551647/2

[jagadeshjai]

@AlexeyBarabash Can I work on this?

[Brave-Matt]

Another user reporting that this happened to them: https://community.brave.com/t/brave-deleted-all-passwords-and-bookmarks/559382/3

I think this issue should be prioritized higher. I'd also like to add that, if the behavior is not to be changed or requires too much overhead at this time, at minimum, users should be warned that the profile they're deleting is part of a Sync chain and that it should be removed from the chain first before they follow through with profile deletion.

cc @AlexeyBarabash

[kjozwiak]

The above requires 1.68.141 or higher for 1.68.x verification 👍

[GeetaSarvadnya]

Verification PASSED on

Brave | 1.68.141 Chromium: 127.0.6533.120 (Official Build) (64-bit)
-- | --
Revision | b3f23500b575d50584510ea1814ef440d30741a8
OS | Windows 10 Version 22H2 (Build 19045.4651)

Reproduced the issue on 1.68.137 Chromium: 127.0.6533.100

Sync chain between Machine 1, Profile 1 on machine 1 and Machine 2

• Imported bookmarks and passwords and opened few sites and added opened sites to the reading list on Machine 1 and then created a sync chain between the Profile 1(which is created on machine 1) and Machine 2 and selected Sync everything on all the devices on sync chain.

1. Synced data shown across all the devices in a sync chain before deleting the Profile 1 on machine 1

Machine 1

Example	Example	Example

Profile 1 on machine 1

Example	Example	Example

Machine 2

Example	Example	Example

2. Delete Profile 1 from machine 1

Example	Example	Example	Example

3. Synced data is NOT shown across all the devices in a sync chain after deleting the Profile 1 on machine 1

Machine 1

Example	Example	Example

Machine 2

Example	Example	Example

Verifying Fix

Using the same STR/Cases mentioned/outlined above, created the same scenario using 1.68.141 Chromium: 127.0.6533.120 as per the following:

1. Synced data shown across all the devices in a sync chain before deleting the Profile 1 on machine 1

Machine 1

Example	Example	Example

Profile 1 on machine 1

Example	Example	Example

Machine 2

Example	Example	Example

2. Delete Profile 1 from machine 1

Example	Example	Example	Example

3. Synced data is shown across all the devices in a sync chain after deleting the Profile 1 on machine 1

Machine 1

Example	Example	Example

Machine 2

Example	Example	Example

[GeetaSarvadnya]

@AlexeyBarabash: When Profile 1 is deleted (via profile manager) on machine 1, the sync data is NOT removed from Machine 1 and Machine 2 as expected. But Profile 1 is not removed from the sync chain even after 15 mins of deletion of profile 1, this is behaving same on 1.68.137 and 1.68.141