Add Discord Join Net Play functionally

Source/Core/DolphinQt2/DiscordHandler.cpp

@@ -0,0 +1,45 @@
+// Copyright 2018 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#include "DolphinQt2/DiscordHandler.h"
+
+#include "Common/Thread.h"
+
+#include "UICommon/DiscordPresence.h"
+
+DiscordHandler::DiscordHandler() = default;
+
+DiscordHandler::~DiscordHandler()
+{
+  Stop();
+}
+
+void DiscordHandler::Start()
+{
+  m_stop_requested.Set(false);
+  m_thread = std::thread(&DiscordHandler::Run, this);
+}
+
+void DiscordHandler::Stop()
+{
+  m_stop_requested.Set(true);
+
+  if (m_thread.joinable())
+    m_thread.join();
+}
+
+void DiscordHandler::DiscordJoin()
+{
+  emit DiscordHandler::Join();
+}
+
+void DiscordHandler::Run()
+{
+  while (!m_stop_requested.IsSet())
+  {
+    Common::SleepCurrentThread(1000 * 2);
+
+    Discord::CallPendingCallbacks();
+  }
+}