code: function readAsText(file) {
          var result = new $.Deferred();
  
          // Measure performance
          var perfTimerName = PerfUtils.markStart("readAsText:\t" + file.fullPath);
          result.always(function () {
              PerfUtils.addMeasurement(perfTimerName);
          });
  
          // Read file
          file.read(function (err, data, encoding, stat) {
              if (!err) {
                  result.resolve(data, stat.mtime);
              } else {
                  result.reject(err);
              }
          });
  
          return result.promise();
      }
docs: Asynchronously reads a file as UTF-8 encoded text.
  @param {!File} file File to read
  @return {$.Promise} a jQuery promise that will be resolved with the
  file's text content plus its timestamp, or rejected with a FileSystemError string
  constant if the file can not be read.