Contact emails
mike...@chromium.org, jadek...@chromium.org
Explainer
https://github.com/WICG/ua-client-hints#explainer-reducing-user-agent-granularity
Specification
https://wicg.github.io/ua-client-hints/#sec-ch-ua-wow64
Summary
The Sec-CH-UA-WoW64 Client Hint is a backwards compatible shim for
sites relying on "WoW64-ness" (32-bit app running in 64-bit
Windows) as they transition from the User-Agent string to UA-CH.
It returns a boolean value.
Blink component
Blink>Network>ClientHints
Motivation
We would like to provide a seamless transition from
User-Agent-based use cases to UA-CH. The "WoW64" bit is the last
missing piece to accomplish this goal.
Initial public proposal
https://github.com/WICG/ua-client-hints/issues/217
Search tags
wow, wow64, ua-ch, uach
TAG review
https://github.com/w3ctag/design-reviews/issues/640 - still open,
but issues have been addressed. I'll ping the existing issue with
this addition so folks are aware, but I don't expect it to change
TAG's stance of UA-CH as a feature.
TAG review status
Issues addressed
Risks
We don’t anticipate any risk here, we’re just moving this bit from
one API to another as a shim.
Interoperability and Compatibility
Interop: Not all browsers expose wow64-ness in the UA string
today, so sites should not treat a false value as meaningful (the
spec allows for always returning false).
Compat: This hint can be thought of as a compatibility shim for
sites migrating from User-Agent to UA-CH, otherwise N/A.
Gecko: Non-harmful on UA-CH, but were they to implement UA-CH I
would not expect them to add this hint (as they don’t expose this
bit in their UA string anymore).
WebKit: No signal. I would also not expect Apple to implement this
one, were they to implmement UA-CH.
Web developers: Mixed signals
(https://github.com/WICG/ua-client-hints/issues/217) We know of at
least one site (Meet) that uses wow64 to prevent sending a 7MB
wasm binary to users were performance is known to be lousy .
Debuggability
Nothing special needed.
Is this feature fully tested by web-platform-tests?
We'll add some.
Flag name
None.
Requires code in //chrome?
False
Estimated milestones
M100
Tracking Bug
https://bugs.chromium.org/p/chromium/issues/detail?id=1288837
Link to entry on the Chrome Platform Status
https://chromestatus.com/feature/5682026601512960
--
You received this message because you are subscribed to the Google Groups "blink-dev" group.
To unsubscribe from this group and stop receiving emails from it, send an email to blink-dev+...@chromium.org.
To view this discussion on the web visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/819ac730-e4f3-44cb-a2f2-1154de41ed6bn%40chromium.org.
To view this discussion on the web visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAFUtAY_q8v5Uyv-LNg-6183b3cMQmsDkKqVmHAXbuouFWLu-4w%40mail.gmail.com.