Codechange: move all input-handling of video-drivers into InputLoop

src/video/sdl_v.h

@@ -36,6 +36,10 @@ public:
 	bool ClaimMousePointer() override;
 
 	const char *GetName() const override { return "sdl"; }
+
+protected:
+	void InputLoop() override;
+
 private:
 	int PollEvent();
 	bool CreateMainSurface(uint w, uint h);