check/colorfont_tables: update conditions

[m4rc1e]

Description

Our current implementation for com.google.fonts/check/colorfont_tables isn't strict enough.

Fixes #3888

@anthrotype Have I covered all the cases?

To Do

• update CHANGELOG.md
• wait for all checks to pass
• request a review

[felipesanches]

Rationale text needs to be updated to reflect the reasoning of these updated check criteria. It currently reads:

No one color font format supports all major user agents, but the combination
of COLR & SVG tables is pretty good.
A smart server could prune away one or the other based on user agent,
and a dumb server will at least have something that works.
Fonts that do not pass this check can be fixed with the maximum_color tool
available at https://github.com/googlefonts/nanoemoji

[felipesanches]

Also, code-tests need to be updated since they're enforcing the incorrect tag "SVG", while it should be "SVG " instead.

[felipesanches]

Docstring on the code-test must also be updated. It still reads as Fonts must have neither or both the tables 'COLR' and 'SVG'."

[felipesanches]

And please, also add a CHANGELOG.md entry.

[m4rc1e]

Done and apologies for the delay. I forgot about this one.

[m4rc1e]

CI errors seem to involve the whole timeout fiasco which #3892 solves.

[m4rc1e]

Merge conflict fixed.

[khaledhosny]

Adobe CC does not support COLR table (and probably will not do any time soon, given the Adobe’s history with SVG table), so if a font for GF want to also support Adobe CC, do you want to force it to ship to versions?

[anthrotype]

hm fair enough.. I would demote that check to a WARNING, saying that COLRv0-only is OK for browser use, unless you really need SVG support for desktop apps that don't support COLR. They probably want to keep things simple and not allow too many options when onboarding new color fonts. /cc @rsheeter

[anthrotype]

@khaledhosny maybe file a separate issue so we can discuss there

[m4rc1e]

@felipesanches PTAL. I keep having to rebase this PR so it'll be good to get this in.

[m4rc1e]

Thank you!