`match_origin_as_fallback` in content_scripts declaration

[oliverdunk]

Chrome supports the match_origin_as_fallback key which allows content scripts to be injected into pages like about:, data: and blob: based on the host's origin. This is not currently supported in Firefox (although support was expressed in #285) or Safari.

Opening this to track the specific key which is related, and likely to be fixed at the same time as, (but somewhat separate) to the problem discussed in #285.

[Rob--W]

FYI from Firefox's perspective I am not only supportive, but I was also involved in the design of the API as expressed at #285 (comment) .

Would you also include the scripting API in this topic? Going forward, we should ideally consider manifest-declared content_scripts along with content scripts registered in the scripting API.

In Firefox, we have this tracking bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1853411 ("Implement matchOriginAsFallback in the scripting.registerContentScripts API")

[oliverdunk]

Would you also include the scripting API in this topic?

I think that makes sense :)

[Rob--W]

This has been implemented in Firefox 128.