nullvideo: initial release of null video backend

Source/Core/VideoBackends/Null/FramebufferManager.h

@@ -0,0 +1,29 @@
+// Copyright 2015 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#include "VideoCommon/FramebufferManagerBase.h"
+
+class XFBSource : public XFBSourceBase
+{
+public:
+  void DecodeToTexture(u32 xfb_addr, u32 fb_width, u32 fb_height) override {}
+  void CopyEFB(float gamma) override {}
+};
+
+class FramebufferManager : public FramebufferManagerBase
+{
+public:
+  std::unique_ptr<XFBSourceBase> CreateXFBSource(unsigned int target_width,
+                                                 unsigned int target_height,
+                                                 unsigned int layers) override
+  {
+    return std::make_unique<XFBSource>();
+  }
+
+  void GetTargetSize(unsigned int* width, unsigned int* height) override {}
+  void CopyToRealXFB(u32 xfb_addr, u32 fb_stride, u32 fb_height, const EFBRectangle& source_rc,
+                     float gamma = 1.0f) override
+  {
+  }
+};