ipc: Add the class HandleWin.

ipc/handle_win.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 IPC_HANDLE_WIN_H_
+#define IPC_HANDLE_WIN_H_
+
+#include <windows.h>
+
+#include "ipc/ipc_export.h"
+#include "ipc/ipc_message_macros.h"
+
+namespace IPC {
+
+// HandleWin is a wrapper around a Windows HANDLE that can be transported
+// across Chrome IPC channels that support attachment brokering. The HANDLE will
+// be duplicated into the destination process.
+class IPC_EXPORT HandleWin {
+ public:
+  enum Permissions {
+    // A placeholder value to be used by the receiving IPC channel, since the
+    // permissions information is only used by the broker process.
+    INVALID,
+    // The new HANDLE will have the same permissions as the old HANDLE.
+    DUPLICATE,
+    // The new HANDLE will have file read and write permissions.
+    FILE_READ_WRITE,
+    MAX_PERMISSIONS = FILE_READ_WRITE
+  };
+
+  HandleWin(const HANDLE& handle, Permissions permissions);
+
+  HANDLE get_handle() const { return handle_; }
+  void set_handle(HANDLE handle) { handle_ = handle; }
+  Permissions get_permissions() const { return permissions_; }
+
+ private:
+  HANDLE handle_;
+  Permissions permissions_;
+};
+
+template <>
+struct IPC_EXPORT ParamTraits<HandleWin> {
+  typedef HandleWin param_type;
+  static void Write(Message* m, const param_type& p);
+  static bool Read(const Message* m, base::PickleIterator* iter, param_type* p);
+  static void Log(const param_type& p, std::string* l);
+};
+
+}  // namespace IPC
+
+#endif  // IPC_HANDLE_WIN_H_