code: function DeleteMultipartUpload(fileUpload) {
              fileUpload.info('will attempt to abort the upload');
  
              fileUpload.abortParts();
  
              var request = {
                  method: 'DELETE',
                  path: '?uploadId=' + fileUpload.uploadId,
                  x_amz_headers: fileUpload.xAmzHeadersCommon,
                  success404: true,
                  step: 'abort'
              };
  
              SignedS3AWSRequest.call(this, fileUpload, request);
          }
docs: http://docs.amazonwebservices.com/AmazonS3/latest/API/mpUploadAbort.html