Revert of chromeos: Convert ash VPNDelegate interface to mojo

ash/mus/vpn_delegate_mus.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 ASH_MUS_VPN_DELEGATE_MUS_H_
+#define ASH_MUS_VPN_DELEGATE_MUS_H_
+
+#include "ash/common/system/chromeos/network/vpn_delegate.h"
+#include "base/macros.h"
+
+namespace ash {
+
+// VPN delegate for mustash. Fetches VPN data from browser process over mojo.
+class VPNDelegateMus : public VPNDelegate {
+ public:
+  VPNDelegateMus();
+  ~VPNDelegateMus() override;
+
+ private:
+  // VPNDelegate:
+  void ShowAddPage(const std::string& extension_id) override;
+
+  DISALLOW_COPY_AND_ASSIGN(VPNDelegateMus);
+};
+
+}  // namespace ash
+
+#endif  // ASH_MUS_VPN_DELEGATE_MUS_H_