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/HTMLVideoElement.webidl

@@ -0,0 +1,22 @@
+/* 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/. */
+
+// https://html.spec.whatwg.org/multipage/#htmlvideoelement
+[Exposed=Window]
+interface HTMLVideoElement : HTMLMediaElement {
+  [HTMLConstructor] constructor();
+
+  // [CEReactions]
+  //          attribute unsigned long width;
+  // [CEReactions]
+  //          attribute unsigned long height;
+  readonly attribute unsigned long videoWidth;
+  readonly attribute unsigned long videoHeight;
+  [CEReactions] attribute DOMString poster;
+};
+
+partial interface HTMLVideoElement {
+  [Pref="media_testing_enabled"]
+  attribute EventHandler onpostershown;
+};