Make mutter manage its own clutter backends

Introduce two new clutter backends: MetaClutterBackendX11 and
MetaClutterBackendNative. They are so far only wrap ClutterBackendX11
and ClutterBackendEglNative respectively, but the aim is to move things
from the original clutter backends when needed.

https://bugzilla.gnome.org/show_bug.cgi?id=768976

src/backends/native/meta-backend-native.c

@@ -38,6 +38,7 @@
 #include "meta-launcher.h"
 #include "backends/meta-cursor-tracker-private.h"
 #include "backends/meta-pointer-constraint.h"
+#include "backends/native/meta-clutter-backend-native.h"
 
 #include <stdlib.h>
 
@@ -241,6 +242,12 @@ pointer_constrain_callback (ClutterInputDevice *device,
   constrain_all_screen_monitors(device, monitors, n_monitors, new_x, new_y);
 }
 
+static ClutterBackend *
+meta_backend_native_create_clutter_backend (MetaBackend *backend)
+{
+  return g_object_new (META_TYPE_CLUTTER_BACKEND_NATIVE, NULL);
+}
+
 static void
 meta_backend_native_post_init (MetaBackend *backend)
 {
@@ -357,7 +364,10 @@ meta_backend_native_class_init (MetaBackendNativeClass *klass)
 
   object_class->finalize = meta_backend_native_finalize;
 
+  backend_class->create_clutter_backend = meta_backend_native_create_clutter_backend;
+
   backend_class->post_init = meta_backend_native_post_init;
+
   backend_class->create_idle_monitor = meta_backend_native_create_idle_monitor;
   backend_class->create_monitor_manager = meta_backend_native_create_monitor_manager;
   backend_class->create_cursor_renderer = meta_backend_native_create_cursor_renderer;

src/backends/native/meta-backend-native.h

@@ -26,6 +26,7 @@
 #define META_BACKEND_NATIVE_H
 
 #include "backends/meta-backend-private.h"
+#include "backends/native/meta-clutter-backend-native.h"
 
 #define META_TYPE_BACKEND_NATIVE             (meta_backend_native_get_type ())
 #define META_BACKEND_NATIVE(obj)             (G_TYPE_CHECK_INSTANCE_CAST ((obj), META_TYPE_BACKEND_NATIVE, MetaBackendNative))

src/backends/native/meta-clutter-backend-native.c

@@ -0,0 +1,49 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
+
+/*
+ * Copyright (C) 2016 Red Hat
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ *
+ * Written by:
+ *     Jonas Ådahl <jadahl@gmail.com>
+ */
+
+#include "config.h"
+
+#include <glib-object.h>
+
+#include "clutter/clutter.h"
+#include "clutter/egl/clutter-backend-eglnative.h"
+#include "backends/native/meta-clutter-backend-native.h"
+
+struct _MetaClutterBackendNative
+{
+  ClutterBackendEglNative parent;
+};
+
+G_DEFINE_TYPE (MetaClutterBackendNative, meta_clutter_backend_native,
+               CLUTTER_TYPE_BACKEND_EGL_NATIVE)
+
+static void
+meta_clutter_backend_native_init (MetaClutterBackendNative *clutter_backend_nativen)
+{
+}
+
+static void
+meta_clutter_backend_native_class_init (MetaClutterBackendNativeClass *klass)
+{
+}

src/backends/native/meta-clutter-backend-native.h

@@ -0,0 +1,38 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
+
+/*
+ * Copyright (C) 2016 Red Hat
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ *
+ * Written by:
+ *     Jonas Ådahl <jadahl@gmail.com>
+ */
+
+#ifndef META_CLUTTER_BACKEND_NATIVE_H
+#define META_CLUTTER_BACKEND_NATIVE_H
+
+#include <glib-object.h>
+
+#include "clutter/clutter.h"
+#include "clutter/egl/clutter-backend-eglnative.h"
+
+#define META_TYPE_CLUTTER_BACKEND_NATIVE (meta_clutter_backend_native_get_type ())
+G_DECLARE_FINAL_TYPE (MetaClutterBackendNative, meta_clutter_backend_native,
+                      META, CLUTTER_BACKEND_NATIVE,
+                      ClutterBackendEglNative)
+
+#endif /* META_CLUTTER_BACKEND_NATIVE_H */