update engine: 32- and 64-bit compile

src/platform/update_engine/decompressing_file_writer_unittest.cc

 // Copyright (c) 2009 The Chromium OS 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 <string.h>
 #include <unistd.h>
 #include <string>
 #include <vector>
 #include <gtest/gtest.h>
 #include "update_engine/decompressing_file_writer.h"
@@ skipping 57 matching lines @@
   const unsigned int k10bytesSize = 10;
   const unsigned int kUncompressedFileSize = strlen(k10bytes) * 1024 * 1024;
   uncompressed_file.Open(kPath.c_str(),
                          O_CREAT | O_LARGEFILE | O_TRUNC | O_WRONLY, 0644);
   for (unsigned int i = 0; i < kUncompressedFileSize / k10bytesSize; i++) {
     ASSERT_EQ(k10bytesSize, uncompressed_file.Write("0123456789", 10));
   }
   uncompressed_file.Close();
 
   // compress the file
-  system((string("cat ") + kPath + " | gzip > " + kPathgz).c_str());
+  EXPECT_EQ(0,
+            system((string("cat ") + kPath + " | gzip > " + kPathgz).c_str()));
 
   // Now read the compressed file and put it into a DecompressingFileWriter
   MockFileWriter mock_file_writer;
   GzipDecompressingFileWriter decompressing_file_writer(&mock_file_writer);
 
   const string path("unused");
   ASSERT_EQ(0, decompressing_file_writer.Open(
       path.c_str(), O_CREAT | O_LARGEFILE | O_TRUNC | O_WRONLY, 0644));
 
   // Open compressed file for reading:
   int fd_in = open(kPathgz.c_str(), O_LARGEFILE | O_RDONLY, 0);
   ASSERT_GE(fd_in, 0);
   char buf[100];
   int sz;
   while ((sz = read(fd_in, buf, sizeof(buf))) > 0) {
     decompressing_file_writer.Write(buf, sz);
   }
   close(fd_in);
   decompressing_file_writer.Close();
 
   ASSERT_EQ(kUncompressedFileSize, mock_file_writer.bytes().size());
   for (unsigned int i = 0; i < kUncompressedFileSize; i++) {
     ASSERT_EQ(mock_file_writer.bytes()[i], '0' + (i % 10)) << "i = " << i;
   }
   unlink(kPath.c_str());
   unlink(kPathgz.c_str());
 }
 
 }  // namespace chromeos_update_engine