Add "has storage access" boolean to environment

[bvandersloot-mozilla]

This is a concept that originated in the Storage Access API, where it has been stuck because of spec issues between Fetch and 6265bis. To un-logjam this, I've started whatwg/fetch#1807. That depends on this bit existing.

This patch adds the bit, which remains false, and does nothing.

• At least two implementers are interested (and none opposed):
  • Mozilla
  • Apple? (@annevk)
  • Google? (@johannhof)
• Tests are written and can be reviewed and commented upon at:
  • change is not observable, not needed?
• Implementation bugs are filed:
  • change is to update spec interfacing, not needed?
• Corresponding HTML AAM & ARIA in HTML issues & PRs:
• MDN issue is filed:
  • I don't think this is needed?
• The top of this comment includes a clear commit message to use.

(See WHATWG Working Mode: Changes for more details.)

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/webappapis.html ( diff )

[johannhof]

To clarify, is this change integrating https://privacycg.github.io/storage-access/#ua-state into HTML? cc @cfredric

If so, that seems fine by me, but I wonder if it should be part of a larger port of the storage access API (🍾 ?)

[annevk]

@domenic would you be okay with this as an incremental step?

[domfarolino]

Different Dom(e|i)nic here, but I'm curious about the "browser support". You marked all browsers as supportive in whatwg/fetch#1807, and I can't really imagine a browser being supportive of that overall effort but objecting on this PR's supplementary bit. I guess my general question is: are all browsers supportive of what exists in https://privacycg.github.io/storage-access/ (https://privacycg.github.io/storage-access/#ua-state specifically)?

Second, should we expect another PR similar to this one to upstream the same bit for "source snapshot params"? What are the plans for that?

This patch adds the bit, which remains false, and does nothing.

This is true from the perspective of the universe of WHATWG standards. But it'd be good to clarify in the commit message/OP that the purpose of this PR is to expose something that will be manipulated and set to true from other specifications, and just needs to appear here so that Fetch can reference it directly.

[annevk]

All browsers are supportive.

And yes, there would be further PRs to upstream the remainder of Storage Access. Pretty much all of Storage Access will end up in HTML.

Good point on being super clear in the commit message.