I don't think we need to follow the general "enable the feature by default" then long later "remove the pref" path, because: 1. this feature is not that complicated so I don't think it would cause any major breakage which would require us to switch it off again; 2. the spec around this feature has been quite stable for a while: some other vendors have been shipping a compitable prefixed version of this feature, and I don't see any major blocker during implementing it. Given this, I believe we can simply remove the pref to enable it directly.

dbaron, what do you think?

One correction: Blink is shipping a mostly compatible prefixed version (whose syntax of text-emphasis-position doesn't match the current spec), and WebKit is shipping a compatible unprefixed version. Those impls haven't yet had the proper behavior for ruby with emphasis marks, though.

Bug 1229609 - Remove layout.css.text-emphasis.enabled pref.

dbaron, could you review this super simple patch?

As we've missed Firefox 45 for enabling text-emphasis, let's wait for the next version to remove the pref.

Comment on attachment 8696528 [details] MozReview Request: Bug 1229609 - Remove layout.css.text-emphasis.enabled pref. Review request updated; see interdiff: https://reviewboard.mozilla.org/r/27359/diff/1-2/

Comment on attachment 8696528 [details] MozReview Request: Bug 1229609 - Remove layout.css.text-emphasis.enabled pref. https://reviewboard.mozilla.org/r/27359/#review41941 I think we should wait at least one cycle with the pref enabled on Release (46) before removing the pref.

Comment on attachment 8696528 [details] MozReview Request: Bug 1229609 - Remove layout.css.text-emphasis.enabled pref. Review request updated; see interdiff: https://reviewboard.mozilla.org/r/27359/diff/2-3/

Comment on attachment 8696528 [details] MozReview Request: Bug 1229609 - Remove layout.css.text-emphasis.enabled pref. https://reviewboard.mozilla.org/r/27359/#review52798

https://hg.mozilla.org/integration/mozilla-inbound/rev/03bd76ec05cb9b0765e79ab5077a61a533b40168 Bug 1229609 - Remove layout.css.text-emphasis.enabled pref. r=heycam

I added a comment in: https://developer.mozilla.org/en-US/docs/Web/CSS/text-emphasis#Browser_compatibility and in: https://developer.mozilla.org/en-US/Firefox/Releases/49#CSS