renderer_opengl: Move Frame/FrameMailbox to OpenGL namespace.

src/core/frontend/emu_window.h

@@ -12,45 +12,6 @@
 
 namespace Core::Frontend {
 
-struct Frame;
-/**
- * For smooth Vsync rendering, we want to always present the latest frame that the core generates,
- * but also make sure that rendering happens at the pace that the frontend dictates. This is a
- * helper class that the renderer can define to sync frames between the render thread and the
- * presentation thread
- */
-class TextureMailbox {
-public:
-    virtual ~TextureMailbox() = default;
-
-    /**
-     * Recreate the render objects attached to this frame with the new specified width/height
-     */
-    virtual void ReloadRenderFrame(Frontend::Frame* frame, u32 width, u32 height) = 0;
-
-    /**
-     * Recreate the presentation objects attached to this frame with the new specified width/height
-     */
-    virtual void ReloadPresentFrame(Frontend::Frame* frame, u32 width, u32 height) = 0;
-
-    /**
-     * Render thread calls this to get an available frame to present
-     */
-    virtual Frontend::Frame* GetRenderFrame() = 0;
-
-    /**
-     * Render thread calls this after draw commands are done to add to the presentation mailbox
-     */
-    virtual void ReleaseRenderFrame(Frame* frame) = 0;
-
-    /**
-     * Presentation thread calls this to get the latest frame available to present. If there is no
-     * frame available after timeout, returns the previous frame. If there is no previous frame it
-     * returns nullptr
-     */
-    virtual Frontend::Frame* TryGetPresentFrame(int timeout_ms) = 0;
-};
-
 /**
  * Represents a graphics context that can be used for background computation or drawing. If the
  * graphics backend doesn't require the context, then the implementation of these methods can be
@@ -168,8 +129,6 @@ public:
      */
     void UpdateCurrentFramebufferLayout(unsigned width, unsigned height);
 
-    std::unique_ptr<TextureMailbox> mailbox;
-
 protected:
     EmuWindow();
     virtual ~EmuWindow();