YouTube: XMLHttpRequest send() method freezes tab/page

[drunkwinter]

Description

Related to issue: zerodytrash/Simple-YouTube-Age-Restriction-Bypass#236

Calling the XMLHttpRequest send() method after calling open() with this specific URL /youtubei/v1/player freezes the tab.

Repro:

const xmlhttp = new XMLHttpRequest();
xmlhttp.open('POST', '/youtubei/v1/player', false);
xmlhttp.send();

Steps to Reproduce

1. Run JS repro provided above.
2. Observe tab freezing after send() call.

Actual result:

Tab freezes after XMLHttpRequest send() method call

Expected result:

Tab should not freeze.

Reproduces how often:

Every time consistently. (Not in a private window)

Brave version (brave://version info)

1.64.116

Version/Channel Information:

Only tested this in stable, but reportedly this is also reproducible in beta, as well as canary. (zerodytrash/Simple-YouTube-Age-Restriction-Bypass#236)

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields?
  No.
• Does the issue resolve itself when disabling Brave Rewards?
  No.
• Is the issue reproducible on the latest version of Chrome?
  No.

[drunkwinter]

The issue is not reproducible in a private window.

[ShivanKaul]

What website are you running this via DevTools? The URL provided is a relative URL.

[drunkwinter]

What website are you running this via DevTools? The URL provided is a relative URL.

Sorry, I thought the title was clear. This can be reproduced by running the repro in DevTools on youtube.com

[drunkwinter]

Alright, so I'm not able to repro this anymore after having reinstalled Brave. Will investigate further.

[ShivanKaul]

I can't repro either, testing on Linux. Lmk if you run into it again.

[ghost]

@ShivanKaul i still have the bug after reinstalling brave on linux and windows. could it be possible that you don't have it/no longer have it after reinstall because https://griffin.brave.com/ enabled/disabled some flags related to the problem?

private window doesn't have this bug and brave beta Version 1.65.89 Chromium: 123.0.6312.58 also doesnt, only newer versions

[drunkwinter]

I had some time to test this with the Nightly build (v1.66.62). And It's consistently reproducible.

No idea why I experienced this on a stable build, but perhaps like indicated by @wratw, experimental flags are being enabled?

Are recent crash reports on YouTube related to this issue? (#37373, #37351, #37298)

[ShivanKaul]

@drunkwinter does the issue happen even with Shields off on youtube.com?

[drunkwinter]

@drunkwinter does the issue happen even with Shields off on youtube.com?

Yes

[ShivanKaul]

@bcaller can you help try to repro?

[ShivanKaul]

I can repro this as well (on Mac). Could this be because of the throttling in brave/brave-core#22334? cc @petemill

[ShivanKaul]

Disabling brave://flags/#brave-ai-chat fixes this. cc @rebron