mash: Disable ash_sysui; begin removal.

mash/session/session.h

 // Copyright 2015 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 MASH_SESSION_SESSION_H_
 #define MASH_SESSION_SESSION_H_
 
 #include <map>
 #include <memory>
 
@@ skipping 31 matching lines @@
   void AddScreenlockStateListener(
       mojom::ScreenlockStateListenerPtr listener) override;
   void LockScreen() override;
   void UnlockScreen() override;
 
   // shell::InterfaceFactory<mojom::Session>:
   void Create(const shell::Identity& remote_identity,
               mojom::SessionRequest request) override;
 
   void StartWindowManager();
-  void StartSystemUI();
   void StartAppDriver();
   void StartQuickLaunch();
 
   void StartScreenlock();
   void StopScreenlock();
 
   // Starts the application at |url|, running |restart_callback| if the
   // connection to the application is closed.
   void StartRestartableService(const std::string& url,
                                const base::Closure& restart_callback);
 
   std::map<std::string, std::unique_ptr<shell::Connection>> connections_;
   bool screen_locked_;
   mojo::BindingSet<mojom::Session> bindings_;
   mojo::InterfacePtrSet<mojom::ScreenlockStateListener> screenlock_listeners_;
 
   DISALLOW_COPY_AND_ASSIGN(Session);
 };
 
 }  // namespace session
 }  // namespace mash
 
 #endif  // MASH_SESSION_SESSION_H_