Allow cosmetic filtering to override in-page !important styles

[antonok-edm]

Followup for #17013 (comment)

Steps to reproduce

From an EU IP (the cookie banner does not show up in the US):

1. go to brave://adblock
2. Set the Custom Filters textarea to just ###cookiebanner (and nothing else)
3. Go to https://www.circleci.com
4. Obnoxious cookiebanner is displayed (the element containing it is a div with id cookiebanner)

The cookie banner should be hidden; any cosmetic filters entered in brave://adblock's "Custom filters" box should not be subject to first-party exemption heuristics.

[JakobJingleheimer]

Bump. Any chance of a fix for this? It was a great feature 😀

[ceejay2k]

Same Issue for. me You can use right-click on content -> brave -> block element to block a certain element. it only works once (the element is blocked, the rule is added to custom rules, but after reload/restart/new page it is not applied).

i just tried this filter to get an annoying empty space on top of the page gone, obviously its only empty because the ad itself was blocked already:

arstechnica.com##.ad.ad_crown

will not work. now use the context menu to block the same element (the rule was actually created by this) and see what happens (see above).

[antonok-edm]

Finally got a chance to look into this one. It appears to be related to #20177 - i.e., not working in cases where there's an !important added to the display style of the element in question. Not sure how we let this one regress, but I will be working on the fix shortly and making sure there's adequate testing to prevent it from happening again.

[antonok-edm]

Ok, this should be fixed by brave/brave-core#12038 in the next Nightly build - please let me know if you see any other issues!