Basic ScrollTimeline implementation for Animation Worklet

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

Index: third_party/WebKit/Source/core/animation/ScrollTimeline.idl
diff --git a/third_party/WebKit/Source/core/animation/ScrollTimeline.idl b/third_party/WebKit/Source/core/animation/ScrollTimeline.idl
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+// 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/#scrolltimeline-interface
+
+[
+    Constructor(optional ScrollTimelineOptions options),
+    ConstructorCallWith=Document,
+    RaisesException=Constructor,
+    RuntimeEnabled=CompositorWorker
+] interface ScrollTimeline : AnimationTimeline {
+    readonly attribute Element? scrollSource;
+    readonly attribute ScrollDirection orientation;
+    readonly attribute (double or ScrollTimelineAutoKeyword) timeRange;
+};