webkit2gtk-web-extension-4.0: add missing *-custom.vala

diff --git a/vapi/metadata/WebKit2WebExtension-4.0-custom.vala b/vapi/metadata/WebKit2WebExtension-4.0-custom.vala
new file mode 100644 (file)
index 0000000..a994a77
--- /dev/null
+++ b/vapi/metadata/WebKit2WebExtension-4.0-custom.vala
@@ -0,0 +1,5 @@
+namespace WebKit {
+       namespace DOM {
+               public delegate void EventTargetFunc (WebKit.DOM.EventTarget target, WebKit.DOM.Event event);
+       }
+}