I'm not sure if there's anything actionable here, but I'm filing it anyways. On OS X, Telemetry seems to suggest that degenerate tab spinning cases took a dip around September 18th (which was around when billm's patches from bug 1279086 went out to users), but it's been on the rise ever since. Here's a graph: https://mzl.la/2d6J8nQ I'm not entirely certain that the dip around September 18th has anything to do with the version change. I'll point out that Windows appears to have kept the improvement that billm's patch caused: https://mzl.la/2d6K4bG

chutten notes that the number of submissions we have for OS X on Nightly is small enough for these variations to be mostly noise. I'm going to close this one out as INVALID.