Labs/Test Pilot/Test Proposals/Bookmarks in Sidebar
It would be nice to test how much of our Firefox users need the "Open this bookmark in the sidebar" feature. If this is just used by a few people, we'd discuss to kill this feature. Therefore we really need a test to be sure we don't kill a feature that is widely used. Please see https://bugzilla.mozilla.org/show_bug.cgi?id=560305#c4 .