GPU: Factor out the framebuffer configuration code for both Clear and Draw commands.

src/video_core/renderer_opengl/gl_rasterizer.h

@@ -7,6 +7,7 @@
 #include <array>
 #include <cstddef>
 #include <memory>
+#include <utility>
 #include <vector>
 #include <glad/glad.h>
 #include "common/common_types.h"
@@ -82,6 +83,10 @@ private:
         u32 border_color_a;
     };
 
+    /// Configures the color and depth framebuffer states and returns the dirty <Color, Depth>
+    /// surfaces if writing was enabled.
+    std::pair<Surface, Surface> ConfigureFramebuffers();
+
     /// Binds the framebuffer color and depth surface
     void BindFramebufferSurfaces(const Surface& color_surface, const Surface& depth_surface,
                                  bool has_stencil);