AU: Use Omaha ID rather than MAC address in delta updater

src/platform/update_engine/test_utils.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 "update_engine/test_utils.h"
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <set>
 #include <string>
 #include <vector>
 #include "base/string_util.h"
 #include "chromeos/obsolete_logging.h"
 
 #include "update_engine/file_writer.h"
 #include "update_engine/filesystem_iterator.h"
 #include "update_engine/utils.h"
 
 using std::set;
 using std::string;
 using std::vector;
 
 namespace chromeos_update_engine {
 
-bool WriteFile(const char* path, const char* data, int data_len) {
-  DirectFileWriter writer;
-  TEST_AND_RETURN_FALSE_ERRNO(0 == writer.Open(path,
-                                               O_WRONLY | O_CREAT | O_TRUNC,
-                                               0666));
-  ScopedFileWriterCloser closer(&writer);
-  TEST_AND_RETURN_FALSE_ERRNO(data_len == writer.Write(data, data_len));
-  return true;
-}
-
 bool WriteFileVector(const std::string& path, const std::vector<char>& data) {
-  return WriteFile(path.c_str(), &data[0], data.size());
+  return utils::WriteFile(path.c_str(), &data[0], data.size());
 }
 
 bool WriteFileString(const std::string& path, const std::string& data) {
-  return WriteFile(path.c_str(), data.data(), data.size());
+  return utils::WriteFile(path.c_str(), data.data(), data.size());
 }
 
 off_t FileSize(const string& path) {
   struct stat stbuf;
   int rc = stat(path.c_str(), &stbuf);
   CHECK_EQ(rc, 0);
   if (rc < 0)
     return rc;
   return stbuf.st_size;
 }
@@ skipping 211 matching lines @@
   EXPECT_TRUE(expected_paths.empty());
   if (!expected_paths.empty()) {
     for (set<string>::const_iterator it = expected_paths.begin();
          it != expected_paths.end(); ++it) {
       LOG(INFO) << "extra path: " << *it;
     }
   }
 }
 
 }  // namespace chromeos_update_engine