display: Remove the RENDER extension requirement

Surprisingly, it's completely unused across all of the codebase.

configure.ac

@@ -74,7 +74,7 @@ MUTTER_PC_MODULES="
    pango >= 1.2.0
    cairo >= 1.10.0
    gsettings-desktop-schemas >= 3.7.3
-   xcomposite >= 0.2 xfixes xrender xdamage xi >= 1.6.0
+   xcomposite >= 0.2 xfixes xdamage xi >= 1.6.0
    $CLUTTER_PACKAGE >= 1.17.5
    cogl-1.0 >= 1.17.1
    upower-glib >= 0.99.0
@@ -288,7 +288,7 @@ AC_CHECK_LIB(Xrandr, XRRUpdateConfiguration,
                [AC_CHECK_HEADER(X11/extensions/Xrandr.h,
                                 RANDR_LIBS=-lXrandr found_randr=yes,,
 				[#include <X11/Xlib.h>])],
-               , -lXrender -lXext $ALL_X_LIBS)
+               , -lXext $ALL_X_LIBS)
 
 if test "x$found_randr" = "xyes"; then
    AC_DEFINE(HAVE_RANDR, , [Have the Xrandr extension library])

src/core/display-private.h

@@ -265,9 +265,6 @@ struct _MetaDisplay
   /* Managed by compositor.c */
   MetaCompositor *compositor;
 
-  int render_event_base;
-  int render_error_base;
-
   int composite_event_base;
   int composite_error_base;
   int composite_major_version;
@@ -303,8 +300,6 @@ struct _MetaDisplay
 #else
 #define META_DISPLAY_HAS_SHAPE(display) FALSE
 #endif
-  unsigned int have_render : 1;
-#define META_DISPLAY_HAS_RENDER(display) ((display)->have_render)
   unsigned int have_composite : 1;
   unsigned int have_damage : 1;
 #define META_DISPLAY_HAS_COMPOSITE(display) ((display)->have_composite)

src/core/display.c

@@ -58,7 +58,6 @@
 #include <X11/extensions/shape.h>
 #endif
 #include <X11/Xcursor/Xcursor.h>
-#include <X11/extensions/Xrender.h>
 #include <X11/extensions/Xcomposite.h>
 #include <X11/extensions/Xdamage.h>
 #include <X11/extensions/Xfixes.h>
@@ -363,12 +362,10 @@ static void
 enable_compositor (MetaDisplay *display)
 {
   if (!META_DISPLAY_HAS_COMPOSITE (display) ||
-      !META_DISPLAY_HAS_DAMAGE (display) ||
+      !META_DISPLAY_HAS_DAMAGE (display))
-      !META_DISPLAY_HAS_RENDER (display))
     {
       meta_warning ("Missing %s extension required for compositing",
-                    !META_DISPLAY_HAS_COMPOSITE (display) ? "composite" :
+                    !META_DISPLAY_HAS_COMPOSITE (display) ? "composite" : "damage");
-                    !META_DISPLAY_HAS_DAMAGE (display) ? "damage" : "render");
       return;
     }
 
@@ -627,27 +624,6 @@ meta_display_open (void)
   meta_verbose ("Not compiled with Shape support\n");
 #endif /* !HAVE_SHAPE */
 
-  {
-    the_display->have_render = FALSE;
-    
-    the_display->render_error_base = 0;
-    the_display->render_event_base = 0;
-    
-    if (!XRenderQueryExtension (the_display->xdisplay,
-                                &the_display->render_event_base,
-                                &the_display->render_error_base))
-      {
-        the_display->render_error_base = 0;
-        the_display->render_event_base = 0;
-      }
-    else
-      the_display->have_render = TRUE;
-    
-    meta_verbose ("Attempted to init Render, found error base %d event base %d\n",
-                  the_display->render_error_base,
-                  the_display->render_event_base);
-  }
-
   {
     the_display->have_composite = FALSE;
 

src/core/frame.c

@@ -27,8 +27,6 @@
 #include <meta/errors.h>
 #include "keybindings-private.h"
 
-#include <X11/extensions/Xrender.h>
-
 #define EVENT_MASK (SubstructureRedirectMask |                     \
                     StructureNotifyMask | SubstructureNotifyMask | \
                     ExposureMask |                                 \