It seems Chrome doesn\'t have an API to open the popup, but has a dedicated system for doing it with a hotkey: _execute_browser_action key in commands
_execute_browser_action
commands
Support for _exectue_browser_action is on its way: https://bugzilla.mozilla.org/show_bug.cgi?id=1246034
_exectue_browser_action
Meanwhile I'm quite sure it's not possible.