Move ScopedTokenPrivilege to chrome/installer/util

chrome/installer/util/scoped_token_privilege.h

+// Copyright 2017 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_INSTALLER_UTIL_SCOPED_TOKEN_PRIVILEGE_H_
+#define CHROME_INSTALLER_UTIL_SCOPED_TOKEN_PRIVILEGE_H_
+
+#include <windows.h>
+
+#include "base/macros.h"
+#include "base/win/scoped_handle.h"
+
+// This class is available for Windows only and will enable the privilege

[grt (UTC plus 2), 2017/06/09 08:35:28]

nit: put this in the "installer" namespace as it was before?

[alito, 2017/06/09 17:20:50]

Done.

+// defined by |privilege_name| on the current process' token. The privilege will
+// be disabled upon the ScopedTokenPrivilege's destruction (unless it was
+// already enabled when the ScopedTokenPrivilege object was constructed).
+// Some privileges might require admin rights to be enabled (check is_enabled()
+// to know whether |privilege_name| was successfully enabled).
+class ScopedTokenPrivilege {
+ public:
+  explicit ScopedTokenPrivilege(const wchar_t* privilege_name);
+  ~ScopedTokenPrivilege();
+
+  // Always returns true unless the privilege could not be enabled.
+  bool is_enabled() const { return is_enabled_; }
+
+ private:
+  // Always true unless the privilege could not be enabled.
+  bool is_enabled_;
+
+  // A scoped handle to the current process' token. This will be closed
+  // preemptively should enabling the privilege fail in the constructor.
+  base::win::ScopedHandle token_;
+
+  // The previous state of the privilege this object is responsible for. As set
+  // by AdjustTokenPrivileges() upon construction.
+  TOKEN_PRIVILEGES previous_privileges_;
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(ScopedTokenPrivilege);
+};
+
+#endif  // CHROME_INSTALLER_UTIL_SCOPED_TOKEN_PRIVILEGE_H_