Refactor AppendToFile and WriteFileDescriptor

third_party/zlib/google/zip_reader.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "third_party/zlib/google/zip_reader.h"
 
 #include "base/bind.h"
 #include "base/files/file.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 313 matching lines @@
                                                   internal::kZipBufSize);
     if (num_bytes_read == 0) {
       // Reached the end of the file.
       break;
     } else if (num_bytes_read < 0) {
       // If num_bytes_read < 0, then it's a specific UNZ_* error code.
       success = false;
       break;
     } else if (num_bytes_read > 0) {
       // Some data is read. Write it to the output file descriptor.
-      if (num_bytes_read !=
-          base::WriteFileDescriptor(fd, buf, num_bytes_read)) {
+      if (!base::WriteFileDescriptor(fd, buf, num_bytes_read)) {
         success = false;
         break;
       }
     }
   }
 
   unzCloseCurrentFile(zip_file_);
   return success;
 }
 #endif  // defined(OS_POSIX)
@@ skipping 110 matching lines @@
                    success_callback,
                    failure_callback,
                    progress_callback,
                    current_progress));
 
   }
 }
 
 
 }  // namespace zip