[mutter] build: Use dbus interface dir from pkg-config

[Jonas Ådahl <jadahl src gnome org>]

commit 6e7316ef11a03e6ccca8828dfc33dcc60af0061e
Author: Arun Raghavan <arun arunraghavan net>
Date:   Wed Feb 26 10:08:56 2020 -0500

    build: Use dbus interface dir from pkg-config
    
    Using 'datadir' breaks prefixed builds (as we look for interface files
    in the prefix we are going to install to).
    
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/1094

 meson.build     | 1 +
 src/meson.build | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/meson.build b/meson.build
index e071a5e40..5463b1a9f 100644
--- a/meson.build
+++ b/meson.build
@@ -127,6 +127,7 @@ xau_dep = dependency('xau')
 ice_dep = dependency('ice')
 atk_dep = dependency('atk', version: atk_req)
 libcanberra_dep = dependency('libcanberra', version: libcanberra_req)
+dbus_dep = dependency('dbus-1')
 
 # For now always require X11 support
 have_x11 = true
diff --git a/src/meson.build b/src/meson.build
index 31840d5bd..85f24e963 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -715,7 +715,7 @@ if have_profiler
     'backends/meta-profiler.h',
   ]
 
-  dbus_interfaces_dir = join_paths(datadir, 'dbus-1', 'interfaces')
+  dbus_interfaces_dir = dbus_dep.get_pkgconfig_variable('interfaces_dir')
   sysprof3_dbus_file = join_paths(dbus_interfaces_dir, 'org.gnome.Sysprof3.Profiler.xml')
 
   dbus_sysprof3_profiler_built_sources = gnome.gdbus_codegen('meta-dbus-sysprof3-profiler',