Revert of Expose scroll customization for touch to JS (behind REF).

Source/core/page/scrolling/ScrollStateCallback.idl

Index: Source/core/page/scrolling/ScrollStateCallback.idl
diff --git a/Source/core/page/scrolling/ScrollStateCallback.idl b/Source/core/page/scrolling/ScrollStateCallback.idl
deleted file mode 100644
index 423710a97e97e0270be4d5466f001183f6e07b3e..0000000000000000000000000000000000000000
--- a/Source/core/page/scrolling/ScrollStateCallback.idl
+++ /dev/null
@@ -1,11 +0,0 @@
-// Copyright 2015 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://docs.google.com/document/d/1VnvAqeWFG9JFZfgG5evBqrLGDZYRE5w6G5jEDORekPY
-
-[
-    RuntimeEnabled=ScrollCustomization
-] callback interface ScrollStateCallback {
-    void handleEvent(ScrollState scrollState);
-};