AU: Implement exponential back off for 500 and 503 HTTP response codes.

main.cc

 // 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.
 
 #include <string>
 #include <tr1/memory>
 #include <vector>
 
+#include <base/at_exit.h>
+#include <base/command_line.h>
+#include <base/logging.h>
+#include <base/string_util.h>
 #include <gflags/gflags.h>
 #include <glib.h>
+#include <metrics/metrics_library.h>
 
-#include "base/at_exit.h"
-#include "base/command_line.h"
-#include "base/logging.h"
-#include "base/string_util.h"
-#include "metrics/metrics_library.h"
 #include "update_engine/dbus_constants.h"
 #include "update_engine/dbus_service.h"
 #include "update_engine/prefs.h"
 #include "update_engine/subprocess.h"
 #include "update_engine/update_attempter.h"
-#include "update_engine/utils.h"
+#include "update_engine/update_check_scheduler.h"
 
 extern "C" {
 #include "update_engine/update_engine.dbusserver.h"
 }
 
 DEFINE_bool(logtostderr, false,
             "Write logs to stderr instead of to a file in log_dir.");
 DEFINE_bool(foreground, false,
             "Don't daemon()ize; run in foreground.");
 
@@ skipping 88 matching lines @@
 
   // Create the dbus service object:
   dbus_g_object_type_install_info(UPDATE_ENGINE_TYPE_SERVICE,
                                   &dbus_glib_update_engine_service_object_info);
   UpdateEngineService* service =
       UPDATE_ENGINE_SERVICE(g_object_new(UPDATE_ENGINE_TYPE_SERVICE, NULL));
   service->update_attempter_ = &update_attempter;
   update_attempter.set_dbus_service(service);
   chromeos_update_engine::SetupDbusService(service);
 
-  update_attempter.InitiatePeriodicUpdateChecks();
+  // Schedule periodic update checks.
+  chromeos_update_engine::UpdateCheckScheduler scheduler(&update_attempter);
+  scheduler.Run();
 
   // Update boot flags after 45 seconds
   g_timeout_add_seconds(45, &chromeos_update_engine::UpdateBootFlags, NULL);
 
   // Run the main loop until exit time:
   g_main_loop_run(loop);
 
   // Cleanup:
   g_main_loop_unref(loop);
   update_attempter.set_dbus_service(NULL);
   g_object_unref(G_OBJECT(service));
 
   LOG(INFO) << "Chrome OS Update Engine terminating";
   return 0;
 }