Revert of chromeos: Convert ash VPNDelegate interface to mojo

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 55 matching lines @@
   UpdateInfo();
   ~UpdateInfo();
 
   UpdateSeverity severity;
   bool update_required;
   bool factory_reset_required;
 };
 
 class CastConfigDelegate;
 class NetworkingConfigDelegate;
+class VPNDelegate;
 
 // SystemTrayDelegate is intended for delegating tasks in the System Tray to the
 // application (e.g. Chrome). These tasks should be limited to application
 // (browser) specific tasks. For non application specific tasks, where possible,
 // components/, chromeos/, device/, etc., code should be used directly. If more
 // than one related method is being added, consider adding an additional
-// specific delegate (e.g. CastConfigDelegate).
+// specific delegate (e.g. VPNDelegate).
 //
 // These methods should all have trivial default implementations for platforms
 // that do not implement the method (e.g. return false or nullptr). This
 // eliminates the need to propagate default implementations across the various
 // 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();
@@ skipping 118 matching lines @@
   // Returns true when the Search key is configured to be treated as Caps Lock.
   virtual bool IsSearchKeyMappedToCapsLock();
 
   // Adding observers that are notified when supervised info is being changed.
   virtual void AddCustodianInfoTrayObserver(
       CustodianInfoTrayObserver* observer);
 
   virtual void RemoveCustodianInfoTrayObserver(
       CustodianInfoTrayObserver* observer);
 
+  // Returns VPNDelegate. May return nullptr.
+  virtual VPNDelegate* GetVPNDelegate() const;
+
   // 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_