Add the xrender backend to the window manager.

main.cc

 // Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <unistd.h>
 
 #include <cmath>
 #include <cstdlib>
 #include <ctime>
 
@@ skipping 38 matching lines @@
 DEFINE_bool(start_profiler, false, "Start profiler at window manager startup.");
 
 using std::string;
 using window_manager::EventLoop;
 using window_manager::RealCompositor;
 using window_manager::RealDBusInterface;
 #if defined(COMPOSITOR_OPENGL)
 using window_manager::RealGLInterface;
 #elif defined(COMPOSITOR_OPENGLES)
 using window_manager::RealGles2Interface;
+#elif defined(COMPOSITOR_XRENDER)
 #else
-#error COMPOSITOR_OPENGL or COMPOSITOR_OPENGLES must be defined
+#error COMPOSITOR_OPENGL, COMPOSITOR_OPENGLES or \
+COMPOSITOR_XRENDER must be defined
 #endif
 using window_manager::RealXConnection;
 using window_manager::WindowManager;
 using window_manager::util::GetTimeAsString;
 using window_manager::util::SetUpLogSymlink;
 
 // This should be adjusted according to number of PROFILER_MARKER_*
 static const int kMaxNumProfilerSymbols = 100;
 
 // Handler called by Chrome logging code on failed asserts.
@@ skipping 69 matching lines @@
     LOG(ERROR) << "Unable to open "
                << (display_name ? display_name : "default display");
     return EXIT_FAILURE;
   }
   XSetIOErrorHandler(HandleXIOError);
 
   RealXConnection xconn(display);
   EventLoop event_loop;
 #if defined(COMPOSITOR_OPENGL)
   RealGLInterface gl_interface(&xconn);
+  RealCompositor compositor(&event_loop, &xconn, &gl_interface);
 #elif defined(COMPOSITOR_OPENGLES)
   RealGles2Interface gl_interface(&xconn);
+  RealCompositor compositor(&event_loop, &xconn, &gl_interface);
+#elif defined(COMPOSITOR_XRENDER)
+  RealCompositor compositor(&event_loop, &xconn);
 #endif
-  RealCompositor compositor(&event_loop, &xconn, &gl_interface);
   RealDBusInterface dbus;
   dbus.Init();
 
   WindowManager wm(&event_loop, &xconn, &compositor, &dbus);
   wm.set_initialize_logging(!FLAGS_logtostderr);
   wm.Init();
 
   // TODO: Need to also use XAddConnectionWatch()?
   const int x11_fd = xconn.GetConnectionFileDescriptor();
   LOG(INFO) << "X11 connection is on fd " << x11_fd;
   event_loop.AddFileDescriptor(
       x11_fd, NewPermanentCallback(&wm, &WindowManager::ProcessPendingEvents));
   event_loop.AddPrePollCallback(
       NewPermanentCallback(&wm, &WindowManager::ProcessPendingEvents));
 
   event_loop.Run();
   return EXIT_SUCCESS;
 }