Recalculate frecency score for all places

frecency.js

var start = Date.now();
var cutoff = (Date.now() - 180 * 86400000) * 1000;
var min_frecency = 50;
PlacesUtils.history.DBConnection.createAsyncStatement(
	'UPDATE moz_places SET ' +
	'visit_count = MAX((SELECT COUNT(*) FROM moz_historyvisits WHERE place_id = moz_places.id AND visit_date > ' + cutoff + '), 1) ' +
	'WHERE frecency > ' + min_frecency
).executeAsync({
	handleCompletion: function() {
		PlacesUtils.history.DBConnection.createAsyncStatement(
			'UPDATE moz_places SET frecency = CALCULATE_FRECENCY(id) WHERE frecency > ' + min_frecency
		).executeAsync({
			handleCompletion: function() {
				NewTabUtils.links.populateCache(null, true);
				let end = Date.now();
				alert('That took ' + (end - start) / 1000 + ' seconds');
			}
		});		
	}
});