There are cases when we asynchronously handle tab events, and therefore try to attach an ID to a tab after it's already been removed. In practice, this will typically only affect tests, since it requires the tab to be removed immediately after a related event is dispatched, but in those cases, it causes a leak, since there's no way for the tab to be removed after the map after that point. We should ideally get rid of those weird async hacks, but either way, we should ensure that we never add a tab to the map after it's already been removed. This patch does that.

Comment on attachment 9010780 [details] Bug 1492990: Make _tabIds map not leak. r=aswan Andrew Swan [:aswan] has approved the revision.

https://hg.mozilla.org/integration/mozilla-inbound/rev/807e9ba8d4b8e1d0d362b96aa9878d966b7f8309 Bug 1492990: Make _tabIds map not leak. r=aswan

Will you require manual testing on this bug? if yes please add some details onto how it should be validated or set the qe-verify- flag. Thanks!