Blink-side contiguous allocation of display items.

Source/platform/graphics/paint/FixedPositionDisplayItem.h

Index: Source/platform/graphics/paint/FixedPositionDisplayItem.h
diff --git a/Source/platform/graphics/paint/FixedPositionDisplayItem.h b/Source/platform/graphics/paint/FixedPositionDisplayItem.h
index f3d84c44d6baed4dbd94aee6fa253fbeb99f0299..c9d5868b546915e7cdbf76ca43e224391fce4cd2 100644
--- a/Source/platform/graphics/paint/FixedPositionDisplayItem.h
+++ b/Source/platform/graphics/paint/FixedPositionDisplayItem.h
@@ -7,19 +7,11 @@
 
 #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)
     {
@@ -27,16 +19,11 @@ public:
 
     virtual void replay(GraphicsContext&) override final { }
     virtual void appendToWebDisplayItemList(WebDisplayItemList*) const override final;
+    void appendByMoving(DisplayItems&) override;
 };
 
 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)
     {
@@ -44,6 +31,7 @@ public:
 
     virtual void replay(GraphicsContext&) override final { }
     virtual void appendToWebDisplayItemList(WebDisplayItemList*) const override final;
+    void appendByMoving(DisplayItems&) override;
 
 private:
 #if ENABLE(ASSERT)