This matches Firefox 4's behavior. Users should be able to opt out of our protections if they so choose.
Created attachment 85815 [details] patch v1
I'm not sure this is a good idea. Even if a user turns off pop-up blocking, then might not expect that script can open the file chooser dialog.
This bug was based on a discussion I had with jnd about improving how we block file dialogs. This probably isn't as important to fix since we landed <http://trac.webkit.org/changeset/81057>, as that patch allows apps that rely on opening file choosers via setTimeout() to continue to work without changing the pop-up blocker pref.
Comment on attachment 85815 [details] patch v1 ok, then r-'ing for now. If someone wants to argue for this, I'll reconsider.