LayoutTests/fast/forms/select-max-length.html sets the length of a 10,000 item select to 0.
This takes a ridiculously long time. Looking in HTMLSelectElement::setLength(), when we shorten a select to length n, we do it by repeatedly removing the element at position n, which moves the whole rest of the list up to fill in the hole.
I'm not sure what the required semantics of this operation are, but removing all these elements at once, or at least removing them from length() down to n, would both be much better.
CCing hyatt because he'll know the right people to care about perf here.
*** This bug has been marked as a duplicate of 24876 ***