* CHROME_LOAD_EXTENSIONS_MANIFEST - An env var with a path to a file
that contains one path per line. These are paths to extensions installed
in chrome that the user wants to load while running system specs.
Useful to run things like Ember Inspector.
* CHROME_DISABLE_FORCE_DEVICE_SCALE_FACTOR - On some systems the
--force-device-scale-factor=1 argument makes the UI for chrome
super small, add a way to disable this.