AU: Nice for 2 hours, then normal priority.

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 116 matching lines @@
   // OmahaRequestAction with that event in the current processor, clears the
   // pending event, updates the status and returns true. Returns false
   // otherwise.
   bool ScheduleErrorEventAction();
 
   // Sets the process priority to |priority| and updates |priority_| if the new
   // |priority| is different than the current |priority_|, otherwise simply
   // returns.
   void SetPriority(utils::ProcessPriority priority);
 
-  // Set the process priority to low and sets up timeout events to increase the
-  // priority gradually to high.
+  // Sets the process priority to low and sets up timeout events to increase it.
   void SetupPriorityManagement();
 
   // Resets the process priority to normal and destroys any scheduled timeout
   // sources.
   void CleanupPriorityManagement();
 
-  // The process priority timeout source callback increases the current priority
-  // by one step (low goes to normal, normal goes to high). Returns true if the
-  // callback must be invoked again after a timeout, or false if GLib can
-  // destroy this timeout source.
+  // The process priority timeout source callback sets the current priority to
+  // normal. Returns false so that GLib destroys the timeout source.
   static gboolean StaticManagePriorityCallback(gpointer data);
   bool ManagePriorityCallback();
 
   // Checks if a full update is needed and forces it by updating the Omaha
   // request params.
   void DisableDeltaUpdateIfNeeded();
 
   // If this was a delta update attempt that failed, count it so that a full
   // update can be tried when needed.
   void MarkDeltaUpdateFailure();
@@ skipping 51 matching lines @@
 
   // 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__