[gnome-books/wip/hadess/flatpak-add-dri] flatpak: Fix ePub view not starting in some cases

[Bastien Nocera <hadess src gnome org>]

commit 3f1f5d55648a55ab4ff297c69e4cff619499f3b4
Author: Bastien Nocera <hadess hadess net>
Date:   Sat Feb 2 13:03:53 2019 +0100

    flatpak: Fix ePub view not starting in some cases
    
    Punch a hole in the sandbox to have access to the GPU, so that the
    Wayland sub-compositor in WebKitGtk can be started.
    
    libEGL warning: wayland-egl: could not open /dev/dri/card0 (No such file or directory)
    WaylandCompositor requires eglCreateImage and eglDestroyImage.
    Nested Wayland compositor could not initialize EGL
    
    Closes: #9

 flatpak/org.gnome.Books.json | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/flatpak/org.gnome.Books.json b/flatpak/org.gnome.Books.json
index 451ae143..60bd889c 100644
--- a/flatpak/org.gnome.Books.json
+++ b/flatpak/org.gnome.Books.json
@@ -11,6 +11,8 @@
         "--share=ipc", "--socket=x11",
         /* Wayland access */
         "--socket=wayland",
+        /* OpenGL access */
+        "--device=dri",
         /* Read-only access to users documents */
         "--filesystem=xdg-documents:ro", "--filesystem=xdg-download:ro",
         /* Needs to talk to the network: */