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/OfflineAudioCompletionEvent.webidl

@@ -0,0 +1,17 @@
+/* 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/. */
+/*
+ * For more information on this interface please see
+ * https://webaudio.github.io/web-audio-api/#offlineaudiocompletionevent
+ */
+
+dictionary OfflineAudioCompletionEventInit : EventInit {
+  required AudioBuffer renderedBuffer;
+};
+
+[Exposed=Window]
+interface OfflineAudioCompletionEvent : Event {
+  [Throws] constructor(DOMString type, OfflineAudioCompletionEventInit eventInitDict);
+  readonly attribute AudioBuffer renderedBuffer;
+};