settings.view.js

this.listenTo(app.settings, 'change', this.refresh.bind(this, 'cache'));

refresh: function(arg) {
	var type;
	if (arg === 'cache') {
		// HACK: 'change' fires twice on settings when resetting,
		// once from resetting to defaults and again from setting the
		// topics. This makes sure that refresh is called only once
		// when resetting.
		if (app.settings.get('topics') === undefined) {
			return;
		}

		type = 'refresh-from-cache';
	} else {
		type = 'refresh';
	}

	chrome.extension.sendMessage({
		type: type
	});
}