Not a lot of explanation here. Is this a super rare occurrence or something? At face value seems like something we should fix soonish.
This should happen only when idle runnables are dispatched from other threads, and that shouldn't happen yet. Yes, we should fix this soon, or at least add an assertion that idle runnables could be dispatched only from the same thread.
The assertion sounds like a very nice idea if we are relying on that invariant at the moment.
I'll add the assertion along with a commo
I'll add the assertion along with a comment that it can be removed if/when we start supporting off thread dispatch.
Created Bug 1315187.