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
new file mode 100644
index 0000000000000000000000000000000000000000..04091130ea4440a40c067d050dee7b5129636fbd
--- /dev/null
+++ b/third_party/WebKit/Source/core/animation/ScrollTimeline.idl
@@ -0,0 +1,16 @@
+// 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,

[alancutter (OOO until 2018), 2017/06/08 05:00:32]

I think you want "Exposed(Window CompositorWorker)" so that the interface isn't
exposed to stable.
We should not be seeing a change to
LayoutTests/webexposed/global-interface-listing-expected.txt.

[smcgruer, 2017/06/08 14:43:47]

Done.

+] interface ScrollTimeline : AnimationTimeline {
+    readonly attribute Element? scrollSource;
+    readonly attribute ScrollDirection orientation;
+    readonly attribute (double or ScrollTimelineAutoKeyword) timeRange;
+};