[glib] Add hb_glib_blob_create() that takes GBytes

src/hb-glib.cc

diff --git a/src/hb-glib.cc b/src/hb-glib.cc
index af43cab..61dff5e 100644
--- a/src/hb-glib.cc
+++ b/src/hb-glib.cc
@@ -382,3 +382,14 @@
   return const_cast<hb_unicode_funcs_t *> (&_hb_glib_unicode_funcs);
 }
 
+hb_blob_t *
+hb_glib_blob_create (GBytes *gbytes)
+{
+  gsize size = 0;
+  gconstpointer data = g_bytes_get_data (gbytes, &size);
+  return hb_blob_create ((const char *) data,
+			 size,
+			 HB_MEMORY_MODE_READONLY,
+			 g_bytes_ref (gbytes),
+			 (hb_destroy_func_t) g_bytes_unref);
+}

src/hb-glib.h

diff --git a/src/hb-glib.h b/src/hb-glib.h
index 63a9d33..1a8f42e 100644
--- a/src/hb-glib.h
+++ b/src/hb-glib.h
@@ -46,6 +46,9 @@
 hb_unicode_funcs_t *
 hb_glib_get_unicode_funcs (void);
 
+hb_blob_t *
+hb_glib_blob_create (GBytes *gbytes);
+
 
 HB_END_DECLS