The problem is that a GC can be triggered in a number of ways, so scheduling zones in nsJSContext::GarbageCollectNow is not effective. This patch schedules these zones in the GC callback, which is always called at the start of GC. This means we have to change the internal logic slightly to allow the GC callback to schedule addional zones; previously this state was saved and restored before/after running the callback.
Differential Revision: https://phabricator.services.mozilla.com/D51145
--HG--
extra : moz-landing-system : lando