Adds a support for compiling flutter engine when
gdk does not have X11 backend. In such a configuration
the generated gdkconfig.h header file looks like the following:
/* gdkconfig.h
*
* This is a generated file. Please modify `configure.ac'
*/
#ifndef __GDKCONFIG_H__
#define __GDKCONFIG_H__
#if !defined (__GDK_H_INSIDE__) && !defined (GDK_COMPILATION)
#error "Only <gdk/gdk.h> can be included directly."
#endif
#include <glib.h>
G_BEGIN_DECLS
#define GDK_WINDOWING_WAYLAND
G_END_DECLS
#endif /* __GDKCONFIG_H__ */
Additionally headers like <gdk/gdkx.h> are not available at all.
Above configuration can be found on the most of the embedded systems.
This patch enables compilation of X11 specific code only when gdk
defines GDK_WINDOWING_X11.
Signed-off-by: Damian Wrobel <dwrobel@ertelnet.rybnik.pl>
