Bug 29757 – Chromium wants to turn off SharedWorkers at runtime

• Component: WebCore JavaScript
• Status: RESOLVED FIXED

[Andrew Wilson]

We need to add SharedWorkerRepository::isAvailable(), and have window.SharedWorker === undefined when isAvailable returns false.

[Andrew Wilson]

Created attachment 40156 [details]
proposed patch

V8 does not support custom getters for constructors yet, so this just turns on this functionality for JSC.

V8 functionality will be added once https://bugs.webkit.org/show_bug.cgi?id=29758 is addressed

[Eric Seidel (no email)]

Comment on attachment 40156 [details]
proposed patch

Where is the code to make it return false?
         // Returns true if the platform supports SharedWorkers, otherwise false.
 52         static bool isAvailable();

[Andrew Wilson]

That will be in the platform specific implementation. Chromium will provide its own implementation of SharedWorkerRepository (it will not compile the default WebKit implementation in DefaultSharedWorkerRepository).

[Eric Seidel (no email)]

Comment on attachment 40156 [details]
proposed patch

Why wouldn't this be held off of Settings?

[Andrew Wilson]

(In reply to comment #4)
> (From update of attachment 40156 [details])
> Why wouldn't this be held off of Settings?

Because it's not intended to be a user setting, and it doesn't make sense to pollute all platforms with extra settings when there's already a clear platform-specific interface to hang this off of.

I'm basically doing the same thing that MediaPlayer::isAvailable() does, so there's ample precedent for putting it here.

[David Levin]

Comment on attachment 40156 [details]
proposed patch

Looks good. Sorry it took me so long to look at this.

[WebKit Commit Bot]

Comment on attachment 40156 [details]
proposed patch

Clearing flags on attachment: 40156

Committed r49130: <http://trac.webkit.org/changeset/49130>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.

[Sam Weinig]

This is wrong.  "SharedWorker" in window will still return true, and that is the way we encourage web developers to due feature detection.

[Andrew Wilson]

(In reply to comment #9)
> This is wrong.  "SharedWorker" in window will still return true, and that is
> the way we encourage web developers to due feature detection.

I've logged two new bugs to track the issues Sam is concerned about, so I'm closing this bug.

https://bugs.webkit.org/show_bug.cgi?id=30240
https://bugs.webkit.org/show_bug.cgi?id=30289