[Slimming Paint] Blink-side contiguous allocation of display items.

Source/platform/graphics/paint/CompositingDisplayItem.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 CompositingDisplayItem_h
 #define CompositingDisplayItem_h
 
 #include "platform/geometry/FloatRect.h"
 #include "platform/graphics/GraphicsTypes.h"
 #include "platform/graphics/paint/DisplayItem.h"
@@ skipping 19 matching lines @@
         , m_opacity(opacity)
         , m_hasBounds(bounds)
         , m_colorFilter(colorFilter)
         {
             if (bounds)
                 m_bounds = FloatRect(*bounds);
         }
 
     virtual void replay(GraphicsContext&) override;
     virtual void appendToWebDisplayItemList(WebDisplayItemList*) const override;
+    virtual void appendByMoving(DisplayItems&) override;
 
 private:
 #ifndef NDEBUG
     virtual void dumpPropertiesAsDebugString(WTF::StringBuilder&) const override;
 #endif
     const SkXfermode::Mode m_xferMode;
     const float m_opacity;
     bool m_hasBounds;
     FloatRect m_bounds;
     ColorFilter m_colorFilter;
 };
 
 class PLATFORM_EXPORT EndCompositingDisplayItem : public PairedEndDisplayItem {
     WTF_MAKE_FAST_ALLOCATED(EndCompositingDisplayItem);
 public:
     static PassOwnPtr<EndCompositingDisplayItem> create(const DisplayItemClientWrapper& client)
     {
         return adoptPtr(new EndCompositingDisplayItem(client));
     }
 
     EndCompositingDisplayItem(const DisplayItemClientWrapper& client)
         : PairedEndDisplayItem(client, EndCompositing) { }
 
     virtual void replay(GraphicsContext&) override;
     virtual void appendToWebDisplayItemList(WebDisplayItemList*) const override;
+    virtual void appendByMoving(DisplayItems&) override;
 
 private:
 #if ENABLE(ASSERT)
     virtual bool isEndAndPairedWith(DisplayItem::Type otherType) const override final { return otherType == BeginCompositing; }
 #endif
 };
 
 } // namespace blink
 
 #endif // CompositingDisplayItem_h