Alors, j'ai fait quelques recherches dans les fichiers config et je trouve ça:
{"account_id_migration_state":2,"account_tracker_service_last_update":"13172996081825759","autofill":{"profile_use_dates_fixed":true},"browser":{"default_browser_infobar_last_declined":"13172996127335673","has_seen_welcome_page":true,"last_known_google_url":"https://www.google.fr/","window_placement":{"bottom":1070,"left":10,"maximized":true,"right":955,"top":35,"work_area_bottom":1080,"work_area_left":0,"work_area_right":1920,"work_area_top":25}},"countryid_at_install":18002,"data_reduction":{"daily_original_length"
J'en déduis que la fenetre doit se lancer maximisée normalement...Bizarre ce truc!