Add 10 minute random fuzz to automatic update check event schedule.

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/utils.h"
 
 #include <sys/mount.h>
 #include <sys/resource.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <dirent.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
 #include <algorithm>
 
 #include "base/file_path.h"
 #include "base/file_util.h"
+#include "base/rand_util.h"
 #include "base/string_util.h"
 #include "base/logging.h"
 #include "update_engine/file_writer.h"
 #include "update_engine/omaha_request_params.h"
 #include "update_engine/subprocess.h"
 
 using std::min;
 using std::string;
 using std::vector;
 
@@ skipping 417 matching lines @@
   LOG(INFO) << "Setting process priority to " << prio;
   TEST_AND_RETURN_FALSE(setpriority(PRIO_PROCESS, 0, prio) == 0);
   return true;
 }
 
 int ComparePriorities(ProcessPriority priority_lhs,
                       ProcessPriority priority_rhs) {
   return static_cast<int>(priority_rhs) - static_cast<int>(priority_lhs);
 }
 
+int FuzzInt(int value, unsigned int range) {
+  int min = value - range / 2;
+  int max = value + range - range / 2;
+  return base::RandInt(min, max);
+}
+
 const char* const kStatefulPartition = "/mnt/stateful_partition";
 
 }  // namespace utils
 
 }  // namespace chromeos_update_engine