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

utils.h

 // Copyright (c) 2010 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.
 
 #ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_UTILS_H__
 #define CHROMEOS_PLATFORM_UPDATE_ENGINE_UTILS_H__
 
 #include <errno.h>
 
 #include <algorithm>
@@ skipping 107 matching lines @@
 // Detects which bootloader this system uses and returns it via the out
 // param. Returns true on success.
 bool GetBootloader(BootLoader* out_bootloader);
 
 // Returns the error message, if any, from a GError pointer.
 const char* GetGErrorMessage(const GError* error);
 
 // Initiates a system reboot. Returns true on success, false otherwise.
 bool Reboot();
 
+// Fuzzes an integer |value| randomly in the range:
+// [value - range / 2, value + range - range / 2]
+int FuzzInt(int value, unsigned int range);
+
 // Log a string in hex to LOG(INFO). Useful for debugging.
 void HexDumpArray(const unsigned char* const arr, const size_t length);
 inline void HexDumpString(const std::string& str) {
   HexDumpArray(reinterpret_cast<const unsigned char*>(str.data()), str.size());
 }
 inline void HexDumpVector(const std::vector<char>& vect) {
   HexDumpArray(reinterpret_cast<const unsigned char*>(&vect[0]), vect.size());
 }
 
 extern const char* const kStatefulPartition;
@@ skipping 191 matching lines @@
     bool _success = (_x);                                                      \
     if (!_success) {                                                           \
       LOG(ERROR) << #_x " failed.";                                            \
       return;                                                                  \
     }                                                                          \
   } while (0)
 
 
 
 #endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_UTILS_H__