Implement Storage API

[Sihui Liu]

Spec: https://storage.spec.whatwg.org

[Radar WebKit Bug Importer]

<rdar://problem/82678873>

[Sam Sneddon [:gsnedders]]

AFAICT, the only thing left to do here is https://github.com/WebKit/WebKit/blob/a121340322ef72e3e303af58db1c88cb23bf397d/Source/WebCore/Modules/storage/StorageManager.idl#L36 :

// FIXME: add Promise<StorageEstimate> estimate();

That said, we don't appear to have any open bug for that?

[Nate Brustein]

I'm not seeing StorageManager.persist() and persisted() work in the way I expect.

Here is what I'm seeing in Safari:

 * storage.persist() will resolve to true
 * In the same session, storage.persisted() will resolve to true
 * After refreshing the page storage.persisted() will resolve to false

I would expect that if storage.persisted() resolved to true in one session, it would still be true in a subsequent session. That's what I'm seeing in Chrome and FF.

Am I misunderstanding the behavior here, or is this unexpected?

[Sihui Liu]

(In reply to Nate Brustein from comment #3)
> I'm not seeing StorageManager.persist() and persisted() work in the way I
> expect.
> 
> Here is what I'm seeing in Safari:
> 
>  * storage.persist() will resolve to true
>  * In the same session, storage.persisted() will resolve to true
>  * After refreshing the page storage.persisted() will resolve to false
> 
> I would expect that if storage.persisted() resolved to true in one session,
> it would still be true in a subsequent session. That's what I'm seeing in
> Chrome and FF.
> 
> Am I misunderstanding the behavior here, or is this unexpected?

Hi, the persisted flag was not persisted (as WebKit didn't evict data on storage pressure), and this particular issue is fixed at https://bugs.webkit.org/show_bug.cgi?id=256483.