As AbstractThread is also a citizen of xpcom, it deserves a place in SyncRunnable.

Review commit: https://reviewboard.mozilla.org/r/50381/diff/#index_header See other reviews: https://reviewboard.mozilla.org/r/50381/

try is green: https://treeherder.mozilla.org/#/jobs?repo=try&revision=2df423f0da0c

Comment on attachment 8748540 [details] MozReview Request: Bug 1269963 - Add a SyncRunnable::DispatchToThread() overload for AbstractThread. r=bobbyholley. https://reviewboard.mozilla.org/r/50381/#review47521 r=me with that fixed ::: xpcom/threads/AbstractThread.cpp:106 (Diff revision 1) > AbstractThread::RequiresTailDispatch(AbstractThread* aThread) const > { > // We require tail dispatch if both the source and destination > // threads support it. > - return SupportsTailDispatch() && aThread->SupportsTailDispatch(); > + return SupportsTailDispatch() && aThread && aThread->SupportsTailDispatch(); > } Instead of doing this, I would prefer to add a helper called: RequiresTailDispatchFromCurrentThread() { AbstractThread* current = GetCurrent(); return current && RequiresTailDispatch(current); } And then MOZ_ASSERT(aThread) in RequiresTailDispatch. We can also use this new helper from the other callers of RequiresTailDispatch.

Thanks for the review!

Comment on attachment 8748540 [details] MozReview Request: Bug 1269963 - Add a SyncRunnable::DispatchToThread() overload for AbstractThread. r=bobbyholley. Approval Request Comment [Feature/regressing bug #]:1269963 [User impact if declined]: Per bug 1274498 comment 4, we want to uplift bug 1270350 to beta (48) to see if crash can be reduced. This bug is the prerequisite of bug 1270350. [Describe test coverage new/current, TreeHerder]: Tested on Central and TreeHerder. [Risks and why]: Low. The change is simple and has been running on Central for weeks without any regression. [String/UUID change made/needed]:none

Comment on attachment 8748540 [details] MozReview Request: Bug 1269963 - Add a SyncRunnable::DispatchToThread() overload for AbstractThread. r=bobbyholley. taking it to fix the crash should be in 48 beta 3