chamilo-lms2/app/Resources/public/assets/modernizr/feature-detects/forms-fileinput.js

// Detects whether input type="file" is available on the platform
// E.g. iOS < 6 and some android version don't support this

//  It's useful if you want to hide the upload feature of your app on devices that
//  don't support it (iphone, ipad, etc).

Modernizr.addTest('fileinput', function() {
    var elem = document.createElement('input');
    elem.type = 'file';
    return !elem.disabled;
});