headless: cleanup HEADLESS definition

Define HEADLESS globally as it is meant to be.

config_host.mk.in

@@ -102,6 +102,7 @@ export ENABLE_GSTREAMER=@ENABLE_GSTREAMER@
 export ENABLE_GTK3=@ENABLE_GTK3@
 export ENABLE_GTK=@ENABLE_GTK@
 export ENABLE_GTK_PRINT=@ENABLE_GTK_PRINT@
+export ENABLE_HEADLESS=@ENABLE_HEADLESS@
 export ENABLE_KAB=@ENABLE_KAB@
 export ENABLE_KDE4=@ENABLE_KDE4@
 export ENABLE_KDE=@ENABLE_KDE@

configure.in

@@ -8108,8 +8108,6 @@ if test "x$enable_headless" = "xyes"; then
     ENABLE_HEADLESS="TRUE"
     SCPDEFS="$SCPDEFS -DHEADLESS"
     R="headless"
-    # this does not work see hack in Library_vcl.mk
-    AC_DEFINE(HEADLESS)
 fi
 AC_SUBST(ENABLE_HEADLESS)
 

solenv/gbuild/gbuild.mk

@@ -237,6 +237,10 @@ ifeq ($(strip $(ENABLE_GRAPHITE)),TRUE)
 gb_GLOBALDEFS += -DENABLE_GRAPHITE
 endif
 
+ifeq ($(strip $(ENABLE_HEADLESS)),TRUE)
+gb_GLOBALDEFS += -DHEADLESS
+endif
+
 ifeq ($(HAVE_THREADSAFE_STATICS),TRUE)
 gb_GLOBALDEFS += -DHAVE_THREADSAFE_STATICS
 endif

vcl/Library_vcl.mk

@@ -456,7 +456,6 @@ $(eval $(call gb_Library_add_cxxflags,vcl,\
     $$(FREETYPE_CFLAGS) \
 ))
 $(eval $(call gb_Library_add_defs,vcl,\
-    -DHEADLESS \
     -DSAL_DLLPREFIX=\"$(gb_Library_SYSPRE)\" \
     -DSAL_DLLPOSTFIX=\"$(gb_Library_OOOEXT)\" \
     -D_XSALSET_LIBNAME=\"$(call gb_Library_get_runtime_filename,spa)\" \