script: Move code generation and webidl files to new script_bindings crate. (#35157)

Signed-off-by: Josh Matthews <josh@joshmatthews.net>

components/script_bindings/webidls/FontFaceSet.webidl

@@ -0,0 +1,49 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+/*
+dictionary FontFaceSetLoadEventInit : EventInit {
+  sequence<FontFace> fontfaces = [];
+};
+
+[Exposed=(Window,Worker)]
+interface FontFaceSetLoadEvent : Event {
+  constructor(DOMString type, optional FontFaceSetLoadEventInit eventInitDict = {});
+  // WebIDL needs to support FrozenArray & SameObject
+  // [SameObject] readonly attribute FrozenArray<FontFace> fontfaces;
+  readonly attribute any fontfaces;
+};
+
+enum FontFaceSetLoadStatus { "loading" , "loaded" };
+*/
+
+// https://drafts.csswg.org/css-font-loading/#FontFaceSet-interface
+[Exposed=(Window,Worker)]
+interface FontFaceSet : EventTarget {
+  // constructor(sequence<FontFace> initialFaces);
+
+  // setlike<FontFace>;
+  // FontFaceSet add(FontFace font);
+  // boolean delete(FontFace font);
+  // undefined clear();
+
+  // events for when loading state changes
+  // attribute EventHandler onloading;
+  // attribute EventHandler onloadingdone;
+  // attribute EventHandler onloadingerror;
+
+  // check and start loads if appropriate
+  // and fulfill promise when all loads complete
+  // Promise<sequence<FontFace>> load(DOMString font, optional DOMString text = " ");
+
+  // return whether all fonts in the fontlist are loaded
+  // (does not initiate load if not available)
+  // boolean check(DOMString font, optional DOMString text = " ");
+
+  // async notification that font loading and layout operations are done
+  readonly attribute Promise<FontFaceSet> ready;
+
+  // loading state, "loading" while one or more fonts loading, "loaded" otherwise
+  // readonly attribute FontFaceSetLoadStatus status;
+};