Non-standard: This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.
 
 The readAsText method is used to read the content of the LockedFile object and provide the result of that reading as a string. In many ways, it performs like the FileReader.readAsText() method. 
  The reading operation starts at the position given by the LockedFile.location property. 
 
var request = instanceOfLockedFile.readAsText(size[, encoding]);
 
 A FileRequest object to handle the success or failure of the operation. In case of success, the request's result is a string representing the data that have been read.