Oops, thank you for fixing the dependency. I have too many open bugzilla tabs, I picked the wrong. ;-) Also thank you for the pointer to bug 1468355. If it's true what Chris said in the other ticket ("the delay seems to be correlated with the number of cookies") it explains why I was not able to reproduce this issue in a new profile.
Bug 1567296 Comment 2 Edit History
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Oops, thank you for fixing the dependency. I have too many open bugzilla tabs, I picked the wrong. ;-) Also thank you for the pointer to bug 1468355. If it's true what Chris said in the other ticket ("the delay seems to be correlated with the number of cookies") it explains why I was not able to reproduce that issue in a new profile.