Gecko uses IncrementalClearCOMRuleArray for rule list, which would be incremental cleared when destructed. This was implemented in bug 861449, which declares that destructing style data may sometimes take longer time then desired. We need to investigate whether it is still an issue for stylo backend, and if so, we may want to integrate the incremental destroyer as well.
status-firefox57=wontfix unless someone thinks this bug should block 57
status-firefox57: --- → wontfix
You need to log in before you can comment on or make changes to this bug.