Extract kArcEnabled preference from ArcSessionManager part 2.

chrome/browser/chromeos/arc/arc_service_launcher.h

 // Copyright 2016 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_ARC_ARC_SERVICE_LAUNCHER_H_
 #define CHROME_BROWSER_CHROMEOS_ARC_ARC_SERVICE_LAUNCHER_H_
 
 #include <memory>
 
 #include "base/macros.h"
 
 class Profile;
 
 namespace arc {
 
+class ArcPlayStoreEnabledPreferenceHandler;
 class ArcServiceManager;
 class ArcSessionManager;
 
 // Detects ARC availability and launches ARC bridge service.
 class ArcServiceLauncher {
  public:
   ArcServiceLauncher();
   ~ArcServiceLauncher();
 
   // This is to access OnPrimaryUserProfilePrepared() only.
   static ArcServiceLauncher* Get();
 
   // Called before the main MessageLooop starts.
   void Initialize();
 
   // Called after the main MessageLoop stops, but before the Profile is
   // destroyed.
   void Shutdown();
 
   // Called when the main profile is initialized after user logs in.
   void OnPrimaryUserProfilePrepared(Profile* profile);
 
  private:
   std::unique_ptr<ArcServiceManager> arc_service_manager_;
   std::unique_ptr<ArcSessionManager> arc_session_manager_;
+  std::unique_ptr<ArcPlayStoreEnabledPreferenceHandler>
+      arc_play_store_enabled_preference_handler_;
 
   DISALLOW_COPY_AND_ASSIGN(ArcServiceLauncher);
 };
 
 }  // namespace arc
 
 #endif  // CHROME_BROWSER_CHROMEOS_ARC_ARC_SERVICE_LAUNCHER_H_