Add the xrender backend to the window manager.

x11/real_x_connection.h

Index: x11/real_x_connection.h
diff --git a/x11/real_x_connection.h b/x11/real_x_connection.h
index 6d74f32bbdd8f0e406ce9520439f513825b4cca2..2c48f19f326c4f720ac84531ec20e2e01c2fcf8b 100644
--- a/x11/real_x_connection.h
+++ b/x11/real_x_connection.h
@@ -18,6 +18,7 @@ extern "C" {
 
 #include "window_manager/geometry.h"
 #include "window_manager/image_enums.h"
+#include "window_manager/math_types.h"
 #include "window_manager/x11/x_connection.h"
 #include "window_manager/x11/x_types.h"
 
@@ -157,6 +158,15 @@ class RealXConnection : public XConnection {
   virtual bool QueryKeyboardState(std::vector<uint8_t>* keycodes_out);
   virtual bool QueryPointerPosition(Point* absolute_pos_out);
   virtual bool SetWindowBackgroundPixmap(XWindow xid, XPixmap pixmap);
+  virtual bool RenderQueryExtension();
+  virtual XPicture RenderCreatePicture(XDrawable drawable, int depth);
+  virtual XPixmap CreatePixmapFromContainer(const ImageContainer* container);
+  virtual void RenderComposite(bool blend, XPicture src, XPicture mask,
+                               XPicture dst, Point srcpos, Point maskpos,
+                               Matrix4 transform, Size size);
+  virtual void RenderFreePicture(XPicture pict);
+  virtual void RenderFillRectangle(XPicture dst, float red, float green,
+                                   float blue, Point pos, Size size);
   // End XConnection methods.
 
   // This convenience function is ONLY available for a real X