The "doh-rollout.self-enabled" pref remains set to true even after removing the add-on

[SoftVision-CarmenFat]

[Affected Platforms]:

• All Windows

[Affected Versions]:

• Firefox Release 70.0.1, Build ID 20191030021342

[Prerequisites]:

• Have the latest 1.1.0rc1 add-on saved on your machine.

[Steps to reproduce]:

1. Open the browser with a new profile.
2. Install the add-on.
3. Add the "doh-rollout.enabled" pref with the "true" value.
4. Click the "Ok, Got it" button from the doorhanger.
5. Navigate to "about:support" and open the Profile folder.
6. Close the browser.
7. Go to "Extensions" subfolder and delete the "doh-rollout@mozilla.org.xpi" add-on.
8. Reopen the browser and navigate to "about:config" page.
9. Observe if the "doh-rollout.self-enabled" pref is set to false.

[Expected result]:

• The "doh-rollout.self-enabled" pref is set to false.

[Actual result]:

• The "doh-rollout.self-enabled" pref remains set to true.

[Notes]:

• According to this documentation, "If DoH is disabled, this is flipped to false".
• This is also reproducible with installing the add-on as temporary.
• I have attached a screen recording of the issue:

[maxxcrawford]

This is expected behavior. Specifically, all the prefs set by this add-on should remain after uninstall.

• doh-rollout.enabled
• doh-rollout.self-enabled
• doh-rollout.previous.trr.mode
• doh-rollout.doorhanger-shown
• doh-rollout.doorhanger-decision
• doh-rollout.disable-heuristics

[maxxcrawford]

@nhi-nguyen Thoughts?

[maxxcrawford]

Specifically, removing the add-on doesn't trigger either of those events.