In start_document_refresh, use register_bottom_half instead of
install_timer if the timeout is 0 because install_timer asserts that it is
given a delay greater than 0.
Add a test case, test/refresh-0timeout.html. Note that
document.browse.minimum_refresh_time must be set to 0 to reproduce the
assertion failure.
start_document_refreshes() performs the NULL-pointer checks that
previously all callers to start_document_refresh() must perform
and then calls start_document_refresh().
start_document_refreshes performs the NULL-pointer checks that previously all callers to start_document_refresh must perform and then calls start_document_refresh.
Pass the session with some get_opt_* calls. These are the low-hanging fruit. Some places will be difficult because we don't have the session or for other reasons.
