[gtk+] Fix document generation in out of tree builds

[Matthias Clasen <matthiasc src gnome org>]

commit 958fc69494d1d4ba4c7008f914945019ec11dc83
Author: Sjoerd Simons <sjoerd luon net>
Date:   Fri Oct 21 15:55:50 2011 +0200

    Fix document generation in out of tree builds
    
    https://bugzilla.gnome.org/show_bug.cgi?id=661032

 docs/reference/gdk/Makefile.am          |    2 +-
 docs/reference/gtk/Makefile.am          |    2 +-
 docs/reference/libgail-util/Makefile.am |    2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/docs/reference/gdk/Makefile.am b/docs/reference/gdk/Makefile.am
index aab34e3..e73c955 100644
--- a/docs/reference/gdk/Makefile.am
+++ b/docs/reference/gdk/Makefile.am
@@ -12,7 +12,7 @@ DOC_MAIN_SGML_FILE=gdk-docs.sgml
 SCAN_OPTIONS=--deprecated-guards="GDK_ENABLE_BROKEN|GDK_DISABLE_DEPRECATED"
 
 # The directory containing the source code. Relative to $(srcdir)
-DOC_SOURCE_DIR=../../../gdk ../../../gdk/x11
+DOC_SOURCE_DIR=$(top_srcdir)/gdk $(top_srcdir)/gdk/x11
 
 # Used for dependencies
 HFILE_GLOB=$(top_srcdir)/gdk/*.h $(top_srcdir)/gdk/x11/gdkx.h
diff --git a/docs/reference/gtk/Makefile.am b/docs/reference/gtk/Makefile.am
index 153ecfc..4e64367 100644
--- a/docs/reference/gtk/Makefile.am
+++ b/docs/reference/gtk/Makefile.am
@@ -12,7 +12,7 @@ DOC_MAIN_SGML_FILE=gtk-docs.sgml
 SCAN_OPTIONS=--deprecated-guards="GTK_ENABLE_BROKEN|GTK_DISABLE_DEPRECATED"
 
 # The directory containing the source code. Relative to $(srcdir)
-DOC_SOURCE_DIR=../../../gtk
+DOC_SOURCE_DIR=$(top_srcdir)/gtk
 
 # Used for dependencies
 HFILE_GLOB=$(top_srcdir)/gtk/*.h
diff --git a/docs/reference/libgail-util/Makefile.am b/docs/reference/libgail-util/Makefile.am
index 3b52a0f..79bb551 100644
--- a/docs/reference/libgail-util/Makefile.am
+++ b/docs/reference/libgail-util/Makefile.am
@@ -9,7 +9,7 @@ DOC_MODULE=gail-libgail-util3
 DOC_MAIN_SGML_FILE=gail-libgail-util-docs.sgml
 
 # The directory containing the source code (if it contains documentation).
-DOC_SOURCE_DIR=../../../libgail-util
+DOC_SOURCE_DIR=$(top_srcdir)/libgail-util
 
 # Used for dependencies
 HFILE_GLOB = $(top_srcdir)/libgail-util/*.h