AtomImpl *atom = he->mAtom; he->mAtom = 0;
AtomTableClearEntry(PLDHashTable *table, PLDHashEntryHdr *entry){  AtomTableEntry *he = NS_STATIC_CAST(AtomTableEntry*, entry);  AtomImpl *atom = he->mAtom;  he->mAtom = 0;  he->keyHash = 0;  // Normal |AtomImpl| atoms are deleted when their refcount hits 0, and  // they then remove themselves from the table.  In other words, they  // are owned by the callers who own references to them.  // |PermanentAtomImpl| permanent atoms ignore their refcount and are  // deleted when they are removed from the table at table destruction.  // In other words, they are owned by the atom table.  if (atom->IsPermanent())    delete atom;}