Destroy the UserManager after ChromeBrowserMainPartsLinux::PostMainMessageLoopRun

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 <string>
 #include <vector>
 
 #include "ash/ash_switches.h"
@@ skipping 854 matching lines @@
 
   // Let the AutomaticRebootManager unregister itself as an observer of several
   // subsystems.
   automatic_reboot_manager_.reset();
 
   // Clean up dependency on CrosSettings and stop pending data fetches.
   KioskAppManager::Shutdown();
 
   chrome::CloseAsh();
 
-  // Destroy the UserManager after ash has been destroyed.
+  ChromeBrowserMainPartsLinux::PostMainMessageLoopRun();
+
+  // Destroy the UserManager after ash has been destroyed and
+  // ChromeBrowserMainPartsLinux::PostMainMessageLoopRun run.  The latter might
+  // trigger MergeSessionThrottle::ShouldShowMergeSessionPage, which requires
+  // the UserManager to exist.
   UserManager::Destroy();
-
-  ChromeBrowserMainPartsLinux::PostMainMessageLoopRun();
 }
 
 void ChromeBrowserMainPartsChromeos::PostDestroyThreads() {
   ChromeBrowserMainPartsLinux::PostDestroyThreads();
   // Destroy DeviceSettingsService after g_browser_process.
   DeviceSettingsService::Shutdown();
 }
 
 void ChromeBrowserMainPartsChromeos::SetupPlatformFieldTrials() {
   SetupZramFieldTrial();
@@ skipping 38 matching lines @@
   trial->AppendGroup("4GB_RAM_4GB_swap", zram_group == '4' ? 1 : 0);
   trial->AppendGroup("4GB_RAM_6GB_swap", zram_group == '5' ? 1 : 0);
   trial->AppendGroup("snow_no_swap", zram_group == '6' ? 1 : 0);
   trial->AppendGroup("snow_1GB_swap", zram_group == '7' ? 1 : 0);
   trial->AppendGroup("snow_2GB_swap", zram_group == '8' ? 1 : 0);
   // This is necessary to start the experiment as a side effect.
   trial->group();
 }
 
 }  //  namespace chromeos