Add a basic demo mode browser test.

chrome/browser/chromeos/idle_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/chromeos/idle_detector.h"
 
 #include "ash/shell.h"
 #include "ash/wm/user_activity_detector.h"
 #include "base/bind.h"
 #include "base/logging.h"
@@ skipping 17 matching lines @@
 }
 
 void IdleDetector::Start(const base::TimeDelta& timeout) {
   timeout_ = timeout;
   if (!ash::Shell::GetInstance()->user_activity_detector()->HasObserver(this))
     ash::Shell::GetInstance()->user_activity_detector()->AddObserver(this);
   ResetTimer();
 }
 
 void IdleDetector::ResetTimer() {
-  if (timer_.IsRunning()) {
+  if (timer_.IsRunning())
     timer_.Reset();
-  } else {
+  else
     timer_.Start(FROM_HERE, timeout_, idle_callback_);
-  }
 }
 
 }  // namespace chromeos