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

Source/core/page/scrolling/ScrollStateCallback.h

-// 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.
-
-#ifndef ScrollStateCallback_h
-#define ScrollStateCallback_h
-
-#include "platform/heap/Handle.h"
-
-namespace blink {
-
-class ScrollState;
-
-enum class NativeScrollBehavior {
-    DisableNativeScroll,
-    PerformBeforeNativeScroll,
-    PerformAfterNativeScroll,
-};
-
-class ScrollStateCallback : public GarbageCollectedFinalized<ScrollStateCallback> {
-public:
-    ScrollStateCallback()
-        : m_nativeScrollBehavior(NativeScrollBehavior::DisableNativeScroll)
-    {
-    }
-
-    virtual ~ScrollStateCallback()
-    {
-    }
-
-    DEFINE_INLINE_VIRTUAL_TRACE() {}
-    virtual void handleEvent(ScrollState*) = 0;
-
-    void setNativeScrollBehavior(NativeScrollBehavior nativeScrollBehavior)
-    {
-        m_nativeScrollBehavior = nativeScrollBehavior;
-    }
-
-    NativeScrollBehavior nativeScrollBehavior()
-    {
-        return m_nativeScrollBehavior;
-    }
-
-    static NativeScrollBehavior toNativeScrollBehavior(String nativeScrollBehavior);
-
-protected:
-    NativeScrollBehavior m_nativeScrollBehavior;
-};
-
-} // namespace blink
-
-#endif // ScrollStateCallback_h