bindings: Use IDL dictionary to implement FontFaceSetLoadEventInit

Source/core/css/FontFaceSetLoadEventInit.idl

Index: Source/core/css/FontFaceSetLoadEventInit.idl
diff --git a/Source/modules/notifications/GetNotificationOptions.idl b/Source/core/css/FontFaceSetLoadEventInit.idl
similarity index 52%
copy from Source/modules/notifications/GetNotificationOptions.idl
copy to Source/core/css/FontFaceSetLoadEventInit.idl
index 7ed11aaa37b4cbfe28ddabed476bd21526da63af..e058d33e277f6aed86ee002bd0fdd19b8052db87 100644
--- a/Source/modules/notifications/GetNotificationOptions.idl
+++ b/Source/core/css/FontFaceSetLoadEventInit.idl
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// https://notifications.spec.whatwg.org/#service-worker-api
+// http://dev.w3.org/csswg/css-font-loading/#fontfacesetloadevent
 
-dictionary GetNotificationOptions {
-    DOMString tag = "";
+dictionary FontFaceSetLoadEventInit : EventInit {
+    sequence<FontFace> fontfaces = [];
 };