Central as Beta simulation: Treeherder link: https://treeherder.mozilla.org/?failureClassificationId=3#/jobs?repo=try&revision=8fb0fee57749d0fb437ea895ea2f363517357ac7&filter-resultStatus=testfailed&filter-resultStatus=busted&filter-resultStatus=exception&filter-resultStatus=retry&filter-resultStatus=usercancel&filter-resultStatus=runnable&selectedJob=192052458 Failure log: https://treeherder.mozilla.org/logviewer.html#?job_id=192052458&repo=try&lineNumber=28867 This appears to be caused by Bug 1426100. Bug 1348273 also appears to be related, but this got backed out of central, so i assumed it is not the cause. Alex, can you please take a look?

Comment on attachment 8997681 [details] Bug 1480992 - move function call into diagnostic assert to prevent complains about variable not used in release opt builds. https://reviewboard.mozilla.org/r/261380/#review268536 ::: dom/ipc/ContentChild.cpp:1643 (Diff revision 1) > // future connections as well. We do this for sandboxing, but it also ensures > // that the Activity Monitor will not label the content process as "Not > // responding" because it's not running a native event loop. See bug 1384336. > CGSShutdownServerConnections(); > - CGError result = CGSSetDenyWindowServerConnections(true); > - MOZ_DIAGNOSTIC_ASSERT(result == kCGErrorSuccess); > + MOZ_DIAGNOSTIC_ASSERT( > + CGSSetDenyWindowServerConnections(true) == kCGErrorSuccess CGSSetDenyWindowServerConnections is side-effecting (“set” is a verb; see also bug 1384336 comment #20), and this will remove the call on beta/release, which is not what we want.

Comment on attachment 8997681 [details] Bug 1480992 - move function call into diagnostic assert to prevent complains about variable not used in release opt builds. https://reviewboard.mozilla.org/r/261380/#review268742 r- for the reason :jld said, I'll upload a different patch.

Comment on attachment 8998207 [details] Bug 1480992 - fixed perma-fail compilation warning on beta builds; r?haik Haik Aftandilian [:haik] has approved the revision.

Pushed by archaeopteryx@coole-files.de: https://hg.mozilla.org/integration/autoland/rev/764bcd0ac036 fixed perma-fail compilation warning on beta builds; r=haik

Verified fixed in yesterday's beta simulation: https://treeherder.mozilla.org/#/jobs?repo=try&revision=298c8176c9352679e2287fffa7228013f11f1038&filter-resultStatus=testfailed&filter-resultStatus=busted&filter-resultStatus=exception&filter-resultStatus=retry&filter-resultStatus=usercancel&filter-resultStatus=runnable