chromeos: Don't explicitly set system tray visibility during initialization

ash/common/system/tray/system_tray_delegate.h

 // Copyright (c) 2012 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 ASH_COMMON_SYSTEM_TRAY_SYSTEM_TRAY_DELEGATE_H_
 #define ASH_COMMON_SYSTEM_TRAY_SYSTEM_TRAY_DELEGATE_H_
 
 #include <memory>
 #include <string>
 #include <vector>
@@ skipping 92 matching lines @@
 // implementations of this class. Consumers of this delegate should handle the
 // default return value (e.g. nullptr).
 class ASH_EXPORT SystemTrayDelegate {
  public:
   SystemTrayDelegate();
   virtual ~SystemTrayDelegate();
 
   // Called after SystemTray has been instantiated.
   virtual void Initialize();
 
-  // Returns true if system tray should be visible on startup.
-  virtual bool GetTrayVisibilityOnStartup();
-
   // Gets information about the active user.
   virtual LoginStatus GetUserLoginStatus() const;
 
   // Returns the domain that manages the device, if it is enterprise-enrolled.
   virtual std::string GetEnterpriseDomain() const;
 
   // Returns notification for enterprise enrolled devices.
   virtual base::string16 GetEnterpriseMessage() const;
 
   // Returns the display email of the user that manages the current supervised
@@ skipping 151 matching lines @@
   // Creates a system tray item for display rotation lock.
   // TODO(jamescook): Remove this when mus has support for display management
   // and we have a DisplayManager equivalent. See http://crbug.com/548429
   virtual std::unique_ptr<SystemTrayItem> CreateRotationLockTrayItem(
       SystemTray* tray);
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_SYSTEM_TRAY_SYSTEM_TRAY_DELEGATE_H_