Idle Detection API is back and there is no way to turn it off globally

[Kiyos]

Description

One of the privacy-breaking features of latest Chromium — Idle Detection API — has appeared in Brave 1.34.80. Older release versions did not have this as per team’s official position. But something went wrong. Sites now can request the permission to know when the user is actively using the device and there is no way to either deny it for all sites by default, or to turn it off completely (which could be even better) via UI.

Steps to Reproduce

1. Visit the Idle Detection API test page at https://reillyeon.github.io/scraps/idle.html
2. Observe that the usual red banner at the top of the page (“the Idle Detection API is unavailable”) is now absent
3. Click the “Request Permission” button
4. Observe the “reillyeon.github.io wants to Know when you're actively using the device” popup
5. Click Allow or Deny, then click on the ”View site information” button in the address bar
6. Observe the new “Your device use” permission with the chosen setting, which is also reflected in the log on the test page
7. Go to Site and Shields Settings (brave://settings/content), expand Additional permissions
8. Observe that “Your device use” setting isn’t there
9. Go to Flags (brave://flags/), search for “idle”
10. Observe that nothing is found

Actual result:

Step 2:

Step 4:

Step 6:

Step 8:

Step 10:

Expected result:

The “Idle Detection API is unavailable” banner on the test page is visible and there are no permission prompts.

Reproduces how often:

Easily reproduced.

Brave version (brave://version info)

Brave | 1.34.80 Chromium: 97.0.4692.71 (Official Build) (64-bit)
Revision | adefa7837d02a07a604c1e6eff0b3a09422ab88d-refs/branch-heads/4692@{#1247}
OS | Windows 7 Service Pack 1 (Build 7601.24544)

Version/Channel Information:

• Can you reproduce this issue with the current release?
  Brave is up to date for my OS, so — yes.
• Can you reproduce this issue with the beta channel?
  Version 1.35.82 — yes.
• Can you reproduce this issue with the nightly channel?
  Version 1.36.35 — yes.

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.

Miscellaneous Information:

Related issues: #18409, #18417
I sure hope that this feature has made its way back into the codebase by mistake.

[UjCbFwtBayFM]

Tried reproducing using 1.36.37. Launching Brave in normal mode and trying to request permission using the Idle Detection API test page fails 100% of the time.

No default setting visible at brave://settings/content.

Launching Brave using --enable-features=IdleDetection has the mentioned test tool work correctly, with no "Unavailable API" banner. Default permission setting displays correctly in brave://settings/content.

Setting Block as default does not show permission prompt and tool reports it has been denied.

Setting Allow to ask as default has the permission prompt display correctly, which if overridden is visible on site-specific settings page.

[Kiyos]

There was a strange development today. The red “The Idle Detection API appears not to be supported in your browser” banner on the test page is showing again, as it should. And when I click the Request Permission button, the log says that “IdleDetector is not defined”, again, as it should:

It is very strange indeed, because nothing has changed in my browser. Its version is still 1.34.80, there were no new addons installed, etc.
Either it’s a transient issue (which is bad for debugging, I know), or a remote config has been applied.

[Kiyos]

Smol update:
Version 1.34.81 Chromium: 97.0.4692.99 (Official Build) (64-bit) — the issue cannot be reproduced.

[kjozwiak]

@Kiyos sounds like we can close this one off? Have run into the above since originally reporting it? I tried reproducing it on a clean profile using the following build:

Brave | 1.37.109 Chromium: 100.0.4896.60 (Official Build) (64-bit)
-- | --
Revision | 6a5d10861ce8de5fce22564658033b43cb7de047-refs/branch-heads/4896@{#875}
OS | Windows 11 Version 21H2 (Build 22000.593)

[Kiyos]

I guess we can close this for now, yes. However, I still monitor the situation every day because of its weirdness, and will reopen the issue if needed.