Custom filter lists in Shields don't respect `Expires:` field

[Furax-31]

Description

Custom filters don't update automatically ## Actual result: Custom filters don't update automatically. You have to force the update manually. ## Expected result: Filter lists should update automatically. ## Reproduces how often: Add a list manually, after 3 days it is still not updated ## Desktop Brave version: All nightly build since 1.31.16

[antonok-edm]

@Furax-31 thanks for reporting! Given how recently the subscriptions feature landed, I imagine you're looking at a list with a shorter update interval specified. The lists should update automatically after 7 days. Unfortunately, at the moment, the browser doesn't check any of the list metadata, including the Expires field where a list maintainer can customize this interval - that's definitely planned as a followup improvement. There are some clever load-balancing algorithms in other adblockers which we'd probably want to respect as well (e.g. https://adblockplus.org/blog/downloading-a-file-regularly-how-hard-can-it-be).

I'll leave this issue open to track support for the Expires field, since I hadn't already opened one yet.

On the other hand, if the lists aren't updating soon after 7 days have passed, please let us know as well.

[stephendonner]

Verification PASSED using

Brave | 1.57.36 Chromium: 115.0.5790.171 (Official Build) beta (x86_64)
-- | --
Revision | a4bb683f14dc402f5da13707e13559dc4d5ef08b
OS | macOS Version 11.7.9 (Build 20G1426)

Case 1 - PASSED

### Steps: 1. installed `1.57.36` 2. launched Brave 3. opened `brave://settings/shields/filters` 4. pasted `https://raw.githubusercontent.com/miyurusankalpa/adblock-list-sri-lanka/master/lkfilter.txt` into the `Enter filter list URL` textbox, and clicked `Add` 5. closed Brave 6. opened `Local State` from `/Users/sdonner/Library/Application Support/BraveSoftware/Brave-Browser-Beta` and confirmed `expires` is `120` 7. examined the values for `last_successful_update_attempt` and `last_update_attempt`, which were both `13335905915841497` 8. subtracted `417600000000` (from the example in the test plan) from the above `13335905915841497` and got `13335488315841497` 9. relaunched Brave 10. confirmed `5 days ago` timestamp in `brave://settings/shields/filters` 11. waited 5 minutes 12. confirmed the timestamp didn't update 13. closed Brave 14. subtracted `14,400,000,000` microseconds from `13335488315831497` and replaced the values for `last_successful_update_attempt` and `last_update_attempt` with `13335473915841497` 15. relaunched Brave 16. confirmed timestamp still read `5 days ago` 17. waited 5 minutes 18. confirmed timestamp refreshed with `0 seconds ago` `step 4` | `step 6` | `step 7` | `step 8` | `steps 10-12` | `step 14` | `step 16` | `step 18` ---------|------|------|--|----------|-----------|-----------|--------- | | | | | | |

Case 2 - PASSED

### Steps: 1. installed `1.57.36` 2. launched Brave 3. opened `brave://settings/shields/filters` 4. pasted `https://raw.githubusercontent.com/miyurusankalpa/adblock-list-sri-lanka/master/lkfilter.txt` into the `Enter filter list URL` textbox, and clicked `Add` 5. closed Brave 6. opened `Local State` from `/Users/sdonner/Library/Application Support/BraveSoftware/Brave-Browser-Beta` and confirmed `expires` is `120` 7. examined the values for `last_successful_update_attempt` and `last_update_attempt`, which were both `13335911840504428` 8. subtracted `431520000000` microseconds from `13335911840504428` to get `13335480320504428` 9. replaced the values in step 7 with `13335480320504428` 10. relaunched Brave 11. waited, and noted `5 days ago` last-updated timestamp 12. after about a minute, confirmed the list auto-refreshed, with `0 seconds ago` step 4 | step 6 | step 7 | step 9 | step 11 | step 12 -------|-------|--------|--------|--------|------- | | | | |

[Uni-verse]

Verified on Samsung Galaxy S21 5G using version(s):

Brave   1.57.45 Chromium: 116.0.5845.82 (Official Build) (64-bit) 
Revision    c43241b101a636729252df90d1a1a7b72f2a9f94
OS  Android 13; Build/TP1A.220624.014; 33; REL

Note: QA to spot check custom filters/adblock list to ensure no regressions have occurred since the test plan in https://github.com/brave/brave-core/pull/18836#issue-1748875492 cannot be tested on Android due to restricted access to file system.

• Ensured using ||brave.com custom filter will disable js for brave.com
• Ensured disabling shields will disable the custom filter list and re-enable js on brave.com
• Ensured enabling Bypass Paywalls Clean Filters in adblock filters is removing paywall onnytimes.com`

Allow brave	Brave.com	blocking brave.com	JS disabled	Disabling shields restore site

Default	Bypass paywall enabled	With filter