Revert of Calculate paint invalidation rect for scrollbars

third_party/WebKit/Source/core/paint/PaintInvalidationCapableScrollableArea.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 PaintInvalidationCapableScrollableArea_h
-#define PaintInvalidationCapableScrollableArea_h
-
-#include "core/CoreExport.h"
-#include "platform/geometry/LayoutRect.h"
-#include "platform/scroll/ScrollableArea.h"
-
-namespace blink {
-
-class LayoutBox;
-class LayoutBoxModelObject;
-class LayoutScrollbarPart;
-class PaintInvalidationContainer;
-class PaintInvalidationState;
-
-// Base class of FrameView and PaintLayerScrollableArea to share paint invalidation code.
-// TODO(wangxianzhu): Combine this into PaintLayerScrollableArea when root-layer-scrolls launches.
-class CORE_EXPORT PaintInvalidationCapableScrollableArea : public ScrollableArea {
-public:
-    void willRemoveScrollbar(Scrollbar*, ScrollbarOrientation) override;
-    void invalidatePaintOfScrollControlsIfNeeded(const PaintInvalidationState&, const LayoutBoxModelObject& paintInvalidationContainer);
-
-private:
-    virtual LayoutBox& boxForScrollControlPaintInvalidation() const = 0;
-    virtual LayoutScrollbarPart* scrollCorner() const = 0;
-    virtual LayoutScrollbarPart* resizer() const = 0;
-
-    LayoutRect m_horizontalScrollbarPreviousPaintInvalidationRect;
-    LayoutRect m_verticalScrollbarPreviousPaintInvalidationRect;
-    LayoutRect m_scrollCornerPreviousPaintInvalidationRect;
-};
-
-} // namespace blink
-
-#endif // PaintInvalidationCapableScrollableArea_h