feat: add 'screen' to systemPreferences.getMediaAccessStatus()

[miniak]

Description of Change

Adding screen to systemPreferences.getMediaAccessStatus() as macOS 10.15 Catalina requires consent for capturing the screen contents. Related to #20242.

This permission can only be granted manually in the System Preferences. Therefore systemPreferences.askForMediaAccess() cannot be extended in the same way.

Checklist

• PR description included and stakeholders cc'd
• npm test passes
• tests are changed or added
• relevant documentation is changed or added
• PR title follows semantic commit guidelines
• PR release notes describe the change in a way relevant to app developers, and are capitalized, punctuated, and past tense.

Release Notes

Notes: Added screen to systemPreferences.getMediaAccessStatus() for detecting the new macOS Catalina permissions.

[MarshallOfSound]

What is the proposed behavior / use case of this API for the failure / false case?

What can an app do when this returns false that it couldn't do before? What additional information does this provide that a rejected get media promise doesn't?

[nornagon]

Is a boolean the right return value for this API? Can we capture the difference between "screen capture allowed", "screen capture denied", and "screen capture permission not yet requested"? (Assuming the latter is a possible situation, I'm not too familiar with the Catalina APIs.) Even if that's not yet possible, it might be a good idea to leave the door open to more than 2 states in the future.

[dwilson6]

What is the proposed behavior / use case of this API for the failure / false case?

What can an app do when this returns false that it couldn't do before? What additional information does this provide that a rejected get media promise doesn't?

The getUserMedia promise is currently resolves if permissions aren't granted (at least on 7.x.x, I haven't tried on 8.x.x). The stream captures the user's background and the first frame of the app which initiated the capture and will capture the cursor's movement.

That said, getUserMedia rejecting if the permission isn't granted would make more sense.

Is a boolean the right return value for this API? Can we capture the difference between "screen capture allowed", "screen capture denied", and "screen capture permission not yet requested"? (Assuming the latter is a possible situation, I'm not too familiar with the Catalina APIs.) Even if that's not yet possible, it might be a good idea to leave the door open to more than 2 states in the future.

Currently there are no proper apis in Catalina to determine the state of the screen capture permission. The code referenced by this PR uses a heuristic to determine if the permissions have been granted or not.

[codebytere]

approving again following changes and API-WG consensus!

[release-clerk]

Release Notes Persisted

Added screen to systemPreferences.getMediaAccessStatus() for detecting the new macOS Catalina permissions.

[trop]

I was unable to backport this PR to "8-x-y" cleanly;
you will need to perform this backport manually.

[trop]

@miniak has manually backported this PR to "8-x-y", please check out #21116

[dwilson6]

Could this change be backported to 7-x-y as well so it can be used in an already stable version of electron? I believe the changes used here were present in chromium 77

[CapOM]

Could this change be back ported to 4-2-x branch as well ? Thx!