WIP for display item list backed by ListContainer

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..2734bc9f1b7cfea1bb621a7f9de629e7ccab33ca 100644
--- a/Source/platform/graphics/paint/CachedDisplayItem.h
+++ b/Source/platform/graphics/paint/CachedDisplayItem.h
@@ -14,20 +14,7 @@ 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));
-    }
-
     // 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(); }