Basic ScrollTimeline implementation for Animation Worklet

third_party/WebKit/Source/core/animation/ScrollTimelineOptions.idl

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// https://wicg.github.io/scroll-animations/#dictdef-scrolltimelineoptions
+
+enum ScrollDirection {
+    "auto",
+    "block",
+    "inline",
+};
+
+enum ScrollTimelineAutoKeyword { "auto" };
+
+dictionary ScrollTimelineOptions {
+        Element scrollSource;
+        ScrollDirection orientation = "auto";
+        (double or ScrollTimelineAutoKeyword) timeRange = "auto";
+};