Revert "Correct fixed-position recording for Slimming Paint"

Source/platform/graphics/paint/FixedPositionDisplayItem.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 FixedPositionDisplayItem_h
-#define FixedPositionDisplayItem_h
-
-#include "platform/geometry/LayoutSize.h"
-#include "platform/graphics/paint/DisplayItem.h"
-#include "wtf/FastAllocBase.h"
-#include "wtf/PassOwnPtr.h"
-
-namespace blink {
-
-class PLATFORM_EXPORT BeginFixedPositionDisplayItem : public PairedBeginDisplayItem {
-    WTF_MAKE_FAST_ALLOCATED(BeginFixedPositionDisplayItem);
-public:
-    static PassOwnPtr<BeginFixedPositionDisplayItem> create(const DisplayItemClientWrapper& client)
-    {
-        return adoptPtr(new BeginFixedPositionDisplayItem(client));
-    }
-
-    BeginFixedPositionDisplayItem(const DisplayItemClientWrapper& client)
-        : PairedBeginDisplayItem(client, BeginFixedPosition)
-    {
-    }
-
-    virtual void replay(GraphicsContext&) override final { }
-    virtual void appendToWebDisplayItemList(WebDisplayItemList*) const override final;
-};
-
-class PLATFORM_EXPORT EndFixedPositionDisplayItem : public PairedEndDisplayItem {
-    WTF_MAKE_FAST_ALLOCATED(EndFixedPositionDisplayItem);
-public:
-    static PassOwnPtr<EndFixedPositionDisplayItem> create(const DisplayItemClientWrapper& client)
-    {
-        return adoptPtr(new EndFixedPositionDisplayItem(client));
-    }
-
-    EndFixedPositionDisplayItem(const DisplayItemClientWrapper& client)
-        : PairedEndDisplayItem(client, EndFixedPosition)
-    {
-    }
-
-    virtual void replay(GraphicsContext&) override final { }
-    virtual void appendToWebDisplayItemList(WebDisplayItemList*) const override final;
-
-private:
-#if ENABLE(ASSERT)
-    virtual bool isEndAndPairedWith(const DisplayItem& other) const override final { return other.type() == BeginFixedPosition; }
-#endif
-};
-
-} // namespace blink
-
-#endif // FixedPositionDisplayItem_h