Rewrite host GPU abstraction

- Don't have to repeat the same thing for 4 renderers.
 - Add native Metal renderer.

src/util/gl/context_egl_x11.h

@@ -0,0 +1,25 @@
+// SPDX-FileCopyrightText: 2019-2022 Connor McLaughlin <stenzek@gmail.com>
+// SPDX-License-Identifier: (GPL-3.0 OR CC-BY-NC-ND-4.0)
+
+#pragma once
+#include "context_egl.h"
+
+namespace GL {
+
+class ContextEGLX11 final : public ContextEGL
+{
+public:
+  ContextEGLX11(const WindowInfo& wi);
+  ~ContextEGLX11() override;
+
+  static std::unique_ptr<Context> Create(const WindowInfo& wi, const Version* versions_to_try,
+                                         size_t num_versions_to_try);
+
+  std::unique_ptr<Context> CreateSharedContext(const WindowInfo& wi) override;
+  void ResizeSurface(u32 new_surface_width = 0, u32 new_surface_height = 0) override;
+
+protected:
+  EGLNativeWindowType GetNativeWindow(EGLConfig config) override;
+};
+
+} // namespace GL