import os here = os.path.abspath(os.path.dirname(__file__)) class ChromeHandlerMixin(object): def setUp(self): super(ChromeHandlerMixin, self).setUp() entries = [["content", "marionette-chrome", "chrome/"]] self.handler_id = self.marionette.register_chrome_handler( os.path.join(here, "assets", "chrome.manifest"), entries ) def tearDown(self): if self.handler_id: try: self.marionette.unregister_chrome_handler(self.handler_id) except: # if the session was deleted the chrome handler is no longer known pass super(ChromeHandlerMixin, self).tearDown() @property def chrome_base_url(self): return "chrome://marionette-chrome/content/"