[gtk+] build: Allow using libepoxy as a subproject

[Emmanuele Bassi <ebassi src gnome org>]

commit 55c42b9d255205bffa2a150cf113b1c39732b336
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Tue Aug 22 10:20:45 2017 +0100

    build: Allow using libepoxy as a subproject
    
    Like we do for Graphene, we can build libepoxy as a sub-project of GTK+
    in case we do not find the dependency installed on the system.

 meson.build               |    5 +++--
 subprojects/libepoxy.wrap |    4 ++++
 2 files changed, 7 insertions(+), 2 deletions(-)
---
diff --git a/meson.build b/meson.build
index 7aa4d21..1927931 100644
--- a/meson.build
+++ b/meson.build
@@ -321,13 +321,14 @@ cairo_dep      = dependency('cairo', version: cairo_req)
 pangocairo_dep = dependency('pangocairo', version: cairo_req)
 cairogobj_dep  = dependency('cairo-gobject', version: cairo_req)
 pixbuf_dep     = dependency('gdk-pixbuf-2.0', version: gdk_pixbuf_req)
-epoxy_dep      = dependency('epoxy', version: epoxy_req)
+epoxy_dep      = dependency('epoxy', version: epoxy_req,
+                            fallback: ['libepoxy', 'libepoxy_dep'])
 atk_dep        = dependency('atk', version: atk_req)
 gmodule_dep    = dependency('gmodule-2.0', version: glib_req)
 harfbuzz_dep   = dependency('harfbuzz', version: '>= 0.9', required: false)
 xkbdep         = dependency('xkbcommon', version: xkbcommon_req)
 graphene_dep   = dependency('graphene-gobject-1.0', version: graphene_req,
-                            fallback : ['graphene', 'graphene_dep'])
+                            fallback: ['graphene', 'graphene_dep'])
 
 fontconfig_dep = [] # only used in x11 backend
 atkbridge_dep  = [] # only used in x11 backend
diff --git a/subprojects/libepoxy.wrap b/subprojects/libepoxy.wrap
new file mode 100644
index 0000000..0c481b5
--- /dev/null
+++ b/subprojects/libepoxy.wrap
@@ -0,0 +1,4 @@
+[wrap-git]
+directory=libepoxy
+url=https://github.com/anholt/libepoxy.git
+revision=master