Stop demo mode detection correctly.

chrome/browser/ui/webui/chromeos/login/demo_mode_detector.cc

 // Copyright 2014 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/ui/webui/chromeos/login/demo_mode_detector.h"
 
 #include "base/command_line.h"
 #include "base/prefs/pref_registry_simple.h"
 #include "base/prefs/pref_service.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 36 matching lines @@
       return;
   }
 
   if (IsDerelict())
     StartIdleDetection();
   else
     StartOobeTimer();
 }
 
 void DemoModeDetector::StopDetection() {
+  oobe_timer_.Stop();
   idle_detector_.reset();
 }
 
 // static
 void DemoModeDetector::RegisterPrefs(PrefRegistrySimple* registry) {
   registry->RegisterInt64Pref(prefs::kTimeOnOobe, 0);
 }
 
 // Private methods.
 
@@ skipping 79 matching lines @@
       std::max(std::min(oobe_timer_update_interval_,
                         derelict_detection_timeout_ - time_on_oobe_),
                base::TimeDelta::FromSeconds(0));
 }
 
 bool DemoModeDetector::IsDerelict() {
   return time_on_oobe_ >= derelict_detection_timeout_;
 }
 
 }  // namespace chromeos