>partitioning by eTLD+1 They were already partitioned by the requested eTLD+1, because they were already partitioned by the requested URL, which contains the r

>partitioning by eTLD+1 They were already partitioned by the requested eTLD+1, because they were already partitioned by the requested URL, which contains the requested eTLD+1. Chrome's change was additionally partitioning it by 2 more eTLD+1s: the top-level eTLD+1 and the frame eTLD+1. It looks like Firefox's change was to add 1 eTLD+1 to the original behavior: the top-level eTLD+1.