A quick and dirty way of doing it, could be something like this:
function configurePopupMobileToMaximize (map) {
require(['dojo/aspect'], function(aspect){
aspect.after(map.infoWindow, 'onSelectionChange', function () {
var feature = map.infoWindow.getSelectedFeature();
if (feature !== undefined && map.infoWindow._toggleView) {
map.infoWindow._toggleView();
}
});
});
}
Then just call somewhere this function to configure the behaviour before the user open some popup.
configurePopupMobileToMaximize(myMap);
Now, this uses a "private" function _toogleView() that we probably shouldn't use directly for some reason. Also, you probably should require the aspect module somewhere else (like a define block) and not inside the function.
But it works.