Find cached display items directly during painting

third_party/WebKit/Source/platform/graphics/paint/CachedDisplayItem.h

-// Copyright 2014 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 CachedDisplayItem_h
-#define CachedDisplayItem_h
-
-#include "platform/graphics/paint/DisplayItem.h"
-#include "wtf/Assertions.h"
-
-namespace blink {
-
-// A placeholder of a DrawingDisplayItem or a subtree in the new paint DisplayItemList,
-// to indicate that the DrawingDisplayItem/subtree has not been changed and should be replaced with
-// the cached DrawingDisplayItem/subtree when merging new paint list to cached paint list.
-class CachedDisplayItem final : public DisplayItem {
-public:
-    CachedDisplayItem(const DisplayItemClient& client, Type type)
-        : DisplayItem(client, type, sizeof(*this))
-    {
-        ASSERT(isCachedType(type));
-    }
-
-private:
-    // CachedDisplayItem is never replayed or appended to WebDisplayItemList.
-    void replay(GraphicsContext&) const final { ASSERT_NOT_REACHED(); }
-    void appendToWebDisplayItemList(const IntRect&, WebDisplayItemList*) const final { ASSERT_NOT_REACHED(); }
-};
-
-} // namespace blink
-
-#endif // CachedDisplayItem_h