Blink-side contiguous allocation of display items.

Source/platform/graphics/paint/CachedDisplayItem.h

Index: Source/platform/graphics/paint/CachedDisplayItem.h
diff --git a/Source/platform/graphics/paint/CachedDisplayItem.h b/Source/platform/graphics/paint/CachedDisplayItem.h
index ac8390102cd2f1e6eacc1007e26010a710890b36..dfb43fda376117e9e1af97bcd29f01cffb255df7 100644
--- a/Source/platform/graphics/paint/CachedDisplayItem.h
+++ b/Source/platform/graphics/paint/CachedDisplayItem.h
@@ -14,23 +14,19 @@ namespace blink {
 // the DisplayItem has not been changed and should be replaced with the cached DisplayItem
 // when merging new paint list to cached paint list.
 class PLATFORM_EXPORT CachedDisplayItem : public DisplayItem {
-    WTF_MAKE_FAST_ALLOCATED(CachedDisplayItem);
 public:
-    static PassOwnPtr<CachedDisplayItem> create(const DisplayItemClientWrapper& client, Type type)
-    {
-        return adoptPtr(new CachedDisplayItem(client, type));
-    }
-
-private:
     CachedDisplayItem(const DisplayItemClientWrapper& client, Type type)
         : DisplayItem(client, type)
     {
         ASSERT(isCachedType(type));
     }
 
+private:
     // CachedDisplayItem is never replayed or appended to WebDisplayItemList.
     virtual void replay(GraphicsContext&) override final { ASSERT_NOT_REACHED(); }
     virtual void appendToWebDisplayItemList(WebDisplayItemList*) const override final { ASSERT_NOT_REACHED(); }
+
+    void appendByMoving(DisplayItems&) override;
 };
 
 } // namespace blink