We already were setting the proper Cache-Control headers for the

datagrid listview, which is used for inline reloading of the datagrid

contents. Unfortunately, we didn't have matching headers for the

datagrid pages themselves. This was mostly not noticeable, except for

one highly annoying thing: if you selected a checkbox and then clicked

an action (such as archive), the action would run and everything would

look fine. If the page was then reloaded, Firefox would very helpfully

try to re-select checkbox in the same row number, even though that

didn't correspond to the one that was checked and archived. Setting the

cache headers (in particular, Cache-Control: no-store) turns off this

behavior in Firefox.
While I was doing this I replaced the existing code with Django's

add_never_cache_headers, which does the same thing with less

verbosity.

Ran unit tests.
Selected a review request and clicked "Archive" in the actions

  sidebar. Saw the datagrid update as expected. Clicked the reload

  button in the browser, and saw that Firefox no longer tried to select

  any checkboxes.