Add Quality of Service (QoS) support

Source/Core/Common/QoSSession.h

@@ -0,0 +1,40 @@
+// Copyright 2017 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <enet/enet.h>
+#include <utility>
+
+namespace Common
+{
+class QoSSession
+{
+public:
+  // 1 0 1 1 1 0 0 0
+  // DSCP      ECN
+  static constexpr int ef_tos = 0b10111000;
+
+  QoSSession() = default;
+  QoSSession(ENetPeer* peer, int tos_val = ef_tos);
+
+  ~QoSSession();
+
+  QoSSession& operator=(const QoSSession&) = delete;
+  QoSSession(const QoSSession&) = delete;
+
+  QoSSession& operator=(QoSSession&& session);
+  QoSSession(QoSSession&& session) { *this = std::move(session); }
+  bool Successful() const { return m_success; }
+private:
+#if defined(_WIN32)
+  void* m_qos_handle = nullptr;
+  unsigned long m_qos_flow_id = 0;
+
+  ENetPeer* m_peer = nullptr;
+#endif
+
+  bool m_success = false;
+};
+}  // namespace Common