Change the HTTP error code Brave uses when blocking a network request to better match what other browsers and tools expect, to increase compatibility with crowdsourced filter lists

[pes10k]

A long time ago we started "lying" to pages about scripts being blocked; even when we blocked a script, we didn't throw onerror, we treated it as a 200 empty.

Now that we (all but tiny details) match uBO in capabilities, we should do what uBO does and trigger error path when adblock-rust blocks something

We should continue reporting 200 when we block-but-replace

[bsclifton]

@pes10k does this need QA? If so - can you add steps (and then mark as QA/yes). Also not sure if there's a more concise title we can use for the release notes?

[pes10k]

I dont think this needs a manual QA step, but for release notes, the below should be good i think:

Change the HTTP error code Brave uses when blocking a network request to better match what other browsers and tools expect, to increase compatibility with crowdsourced filter lists

[bsclifton]

@pes10k awesome! updated 😄👌

[bsclifton]

Re-opening after reverting with brave/brave-core#7028

[bsclifton]

Re-opening; this got closed on accident from a rebase (doh)

PR in progress with brave/brave-core#7030

[kjozwiak]

Verification PASSED on Samsung S10+ on Android 10 using 1.16.75 CR: 86.0.4240.193

Ensured that websites listed under brave/brave-core#7030 (comment) didn't cause Brave to crash on both mobile & desktop versions:

• https://www.laredmaspoderosa.com - PASSED (both desktop/mobile versions of website)
• https://www.ilt.edu - PASSED (both desktop/mobile versions of website)
• https://www.hippie-chay.de - PASSED (both desktop/mobile versions of website)
• https://www.wix.com/blog/2016/03/wix-websites-examples - PASSED (both desktop/mobile versions of website)
• https://www.thegivingblock.com - PASSED (both desktop/mobile versions of website)

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Verification passed on Asus Zenfone (x86) with Android 6.0 running 1.16.75 Bravex86.apk

• reproduced the crash using https://www.hippie-chay.de/ on 1.16.74
• upgraded to 1.16.75 and confirmed all sites listed in Explicitly cancel blocked requests (attempt 2) brave-core#7030 (comment) did not crash on launch or after 20s of being on the site
• confirmed for mobile and desktop (using checkbox from 3 dots menu) versions of the site

---

Verification passed on Brave v1.16.75 on Samsung Galaxy Tab S5e (Android 9.0)

• reproduced the crash using https://www.hippie-chay.de/ on 1.16.74
• upgraded to 1.16.75 and confirmed all sites listed in Explicitly cancel blocked requests (attempt 2) brave-core#7030 (comment) did not crash on launch or after 20s of being on the site
• confirmed for mobile and desktop (using checkbox from 3 dots menu) versions of the site

---

Verification on macOS with

Brave | 1.16.75 Chromium: 86.0.4240.193 (Official Build) (x86_64)
-- | --
Revision | 4b1dc838fc8d2b55f2147e7a642b20baf443da5c-refs/branch-heads/4240@{#1411}
OS | macOS Version 10.14.6 (Build 18G6032)

• reproduced the crash using https://www.hippie-chay.de/ on 1.16.72
• using 1.16.75, confirmed all sites listed in Explicitly cancel blocked requests (attempt 2) brave-core#7030 (comment) did not crash on launch or after at least 20s of being on the site

---

Verification passed on

Brave	1.16.75 Chromium: 86.0.4240.193 (Official Build) (64-bit)
Revision	4b1dc838fc8d2b55f2147e7a642b20baf443da5c-refs/branch-heads/4240@{#1411}
OS	Windows 7 Service Pack 1 (Build 7601.24544)

• reproduced the crash using https://www.hippie-chay.de/ on 1.16.72
• using 1.16.75, confirmed all sites listed in Explicitly cancel blocked requests (attempt 2) brave-core#7030 (comment) did not crash on launch or after at least 20s of being on the site

---

Verified passed with

Brave	1.16.75 Chromium: 86.0.4240.193 (Official Build) (64-bit)
Revision	4b1dc838fc8d2b55f2147e7a642b20baf443da5c-refs/branch-heads/4240@{#1411}
OS	Linux

• reproduced the crash using https://www.hippie-chay.de/ on 1.16.72
• using 1.16.75, confirmed all sites listed in Explicitly cancel blocked requests (attempt 2) brave-core#7030 (comment) did not crash on launch or after at least 20s of being on the site