Fix long delays when updating filter lists

[cuba]

Description

When updating filter lists, there may be a long delay before they are ready (over 1 minute).

It is actually caused by an error on the custom filter list screen you can see in the following screenshot (so both will be fixed):

The error causes the engines to not rebuild. Only after delayed task that takes 60s (which forces a necessary rebuild despite some filter list errors) updates the engines.

Steps to reproduce

1. Go to youtube
2. Enable/disable mobile distractions and youtube recommendations filter lists
3. Go back to the page
4. Reload (you might still need to wait about 5 seconds so don't be too quick)

Actual result

Changes will take about a minute to go into effect

Expected result

Changes should be nearly instant (about 5 seconds)

Reproduces how often

Easily reproduced

Brave version

1.69

Device/iOS version

Iphone 14

Affected browser versions

• latest AppStore
• latest TestFlight
• previous TestFlight

Reproducibility

• with Brave Shields disabled
• in the latest version of mobile Safari

Miscellaneous information

No response

[hffvld]

Verified on iPhone 14 using version(s):

Device/OS: iPhone 14 / iOS 17.6
Brave build: 1.68 (117)
BraveCore: 1.68.117 (127.0.6533.26)

---

STEPS:

1. Follow the STR/TP from Fix long delays when updating filter lists #39283 (comment) and Fix issue with long delays when changing enabled filter lists brave-core#24330 (comment)
2. Verify

ACTUAL RESULTS:

• Verified that the delay is no longer than ~5 seconds when enabling/disabling filter lists.
• Verified that error in UI is not shown in CUSTOM FILTERS.
• Verified that ads are blocked on YT with custom filters enabled.

---

1	2	3	4

2024-07-12_17-24-17.mp4