Chrome M121 breaks <ruby> unittest

[tushuhei]

A JavaScript unit test case is failing at https://github.com/google/budoux/actions/runs/7726982481/job/21064428934

 HTMLProcessor.getBlocks should skip <rt> and <rp> elements for <ruby> FAILED

Since the same test case passes on Chrome Headless M120, but not on M121, I believe the change is brought by the Chrome update.

[tushuhei]

@kojiishi Could you take a look at this? It seems the <ruby> tag is treated differently between Chrome M120 and 121.

[kojiishi]

Thanks, I'll take a look. /cc @tkent-google

[kojiishi]

So there was a spec change. The current BudouX has a logic to determine if an element is inline or block:

      return display === 'inline' ? DomAction.Inline : DomAction.Block;

This no longer works since crbug.com/880802, as getComputedStyle(<ruby>).display returns ruby.

The CSS Display multi-keyword syntax also shipped at crbug.com/995106. Looking at this, ruby is probably the only case where we want it to be in-flow.

[tushuhei]

That’s interesting! Thanks for investigating.
Does it make sense to map display==='ruby' to DomAction.Inline, then?