Add a basic demo mode browser test.

chrome/browser/chromeos/idle_detector.h

 // 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_IDLE_DETECTOR_H_
 #define CHROME_BROWSER_CHROMEOS_IDLE_DETECTOR_H_
 
 #include "ash/wm/user_activity_observer.h"
 #include "base/basictypes.h"
+#include "base/callback.h"
 #include "base/compiler_specific.h"
+#include "base/time/time.h"
 #include "base/timer/timer.h"
 
 namespace chromeos {
 
 class IdleDetector : public ash::UserActivityObserver {
  public:
   IdleDetector(const base::Closure& on_active_callback,
                const base::Closure& on_idle_callback);
   virtual ~IdleDetector();
 
@@ skipping 12 matching lines @@
   base::Closure idle_callback_;
 
   base::TimeDelta timeout_;
 
   DISALLOW_COPY_AND_ASSIGN(IdleDetector);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_IDLE_DETECTOR_H_