Implement box-decoration-break:clone everywhere

[mstensho]

WebKittens

@anttijk @alanbaradlay

Title of the spec

CSS Fragmentation

URL to the spec

https://drafts.csswg.org/css-break/#break-decoration

URL to the spec's repository

No response

Issue Tracker URL

No response

Explainer URL

No response

TAG Design Review URL

No response

Mozilla standards-positions issue URL

No response

WebKit Bugzilla URL

https://bugs.webkit.org/show_bug.cgi?id=144249

Radar URL

No response

Description

This is already shipping in Gecko.

As for WebKit and Blink, there's only -webkit-box-decoration-break, and it (i.e. the value 'clone') only works if used on inlines in an inline formatting context.

We also want this in block fragmentation (multicol / pagination), and without having to use the -webkit- prefix.

See https://chromestatus.com/feature/5162398704205824

[marcoscaceres]

Pinging @anttijk @alanbaradlay for visibility.