controllers/ddddddddddddddddddddd/DriveService.gs

function DriveService() {}

DriveService.prototype.saveImageData = function(imageData) {
  var drive = DriveApp.getDrive();
  var folder = drive.getFolderById('your-folder-id');
  var file = folder.createFile(imageData);
  file.setName('image-' + new Date().getTime() + '.jpg');
}