AU: Update status to DOWNLOADING only after receiving some bytes from server.

update_attempter.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_UPDATE_ATTEMPTER_H__
 #define CHROMEOS_PLATFORM_UPDATE_ENGINE_UPDATE_ATTEMPTER_H__
 
 #include <time.h>
 
 #include <tr1/memory>
@@ skipping 69 matching lines @@
 
   // This is the D-Bus service entry point for going through an
   // update. If the current status is idle invokes Update.
   void CheckForUpdate(const std::string& app_version,
                       const std::string& omaha_url);
 
   // Initiates a reboot if the current state is
   // UPDATED_NEED_REBOOT. Returns true on sucess, false otherwise.
   bool RebootIfNeeded();
 
-  // DownloadActionDelegate method
+  // DownloadActionDelegate methods
+  void SetDownloadStatus(bool active);
   void BytesReceived(uint64_t bytes_received, uint64_t total);
 
  private:
   // Sets the status to the given status and notifies a status update
   // over dbus.
   void SetStatusAndNotify(UpdateStatus status);
 
   // Creates an error event object in |error_event_| to be included in
   // an OmahaRequestAction once the current action processor is done.
   void CreatePendingErrorEvent(AbstractAction* action, ActionExitCode code);
@@ skipping 44 matching lines @@
 
   // Pending error event, if any.
   scoped_ptr<OmahaEvent> error_event_;
 
   // Current process priority.
   utils::ProcessPriority priority_;
 
   // The process priority management timeout source.
   GSource* manage_priority_source_;
 
+  // Set to true if an update download is active (and BytesReceived
+  // will be called), set to false otherwise.
+  bool download_active_;
+
   // For status:
   UpdateStatus status_;
   double download_progress_;
   int64_t last_checked_time_;
   std::string new_version_;
   int64_t new_size_;
 
   // Device paramaters common to all Omaha requests.
   OmahaRequestDeviceParams omaha_request_params_;
 
   DISALLOW_COPY_AND_ASSIGN(UpdateAttempter);
 };
 
 }  // namespace chromeos_update_engine
 
 #endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_UPDATE_ATTEMPTER_H__