Do not watch for low disk events in guest mode.

chrome/browser/chromeos/chrome_browser_main_chromeos.cc

 // Copyright (c) 2013 The Chromium 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 "chrome/browser/chromeos/chrome_browser_main_chromeos.h"
 
 #include <stddef.h>
 
 #include <string>
 #include <utility>
@@ skipping 670 matching lines @@
       new RendererFreezer(std::unique_ptr<RendererFreezer::Delegate>(
           new FreezerCgroupProcessManager())));
 
   g_browser_process->platform_part()->InitializeAutomaticRebootManager();
   g_browser_process->platform_part()->InitializeDeviceDisablingManager();
 
   // This observer cannot be created earlier because it requires the shell to be
   // available.
   idle_action_warning_observer_.reset(new IdleActionWarningObserver());
 
-  // Start watching for low disk space events to notify the user.
-  low_disk_notification_.reset(new LowDiskNotification());
+  // Start watching for low disk space events to notify the user if it is not a
+  // guest profile.
+  if (!user_manager::UserManager::Get()->IsLoggedInAsGuest())
+    low_disk_notification_.reset(new LowDiskNotification());
 
   // Authenticate the user for PIN quick unlock.
   PinStorage* pin_storage = PinStorageFactory::GetForProfile(profile());
   if (pin_storage)
     pin_storage->MarkStrongAuth();
 
   ChromeBrowserMainPartsLinux::PostProfileInit();
 }
 
 void ChromeBrowserMainPartsChromeos::PreBrowserStart() {
@@ skipping 189 matching lines @@
   // Destroy DBus services immediately after threads are stopped.
   dbus_services_.reset();
 
   ChromeBrowserMainPartsLinux::PostDestroyThreads();
 
   // Destroy DeviceSettingsService after g_browser_process.
   DeviceSettingsService::Shutdown();
 }
 
 }  //  namespace chromeos