After removing per-Attribute style declarations, we don't need to GC the matched declaration cache anymore.
Created attachment 125503 [details] Patch
Comment on attachment 125503 [details] Patch Asserting that we have nothing in the cache that is kept alive by it only would be good. We might end up putting this back in if we again start caching something that is not tied to the style selector life time...
Comment on attachment 125503 [details] Patch Clearing r? since Antti brings up a sort-of reason to keep this code around for now.
We need this for now.