Наследование: MobileServiceFileOperation
 private bool ValidateOperation(DeleteMobileServiceFileOperation operation)
 {
     return operation.FileId == this.inputFile.Id &&
         operation.Kind == FileOperationKind.Delete &&
         operation.State == FileOperationState.Pending;
 }
        public async Task DeleteFileAsync(MobileServiceFile file)
        {
            var operation = new DeleteMobileServiceFileOperation(Guid.NewGuid().ToString(), file.Id);

            await QueueOperationAsync(operation);

            NotifyFileOperationCompletion(file, FileOperationKind.Delete, FileOperationSource.Local);
        }