WIP for display item list backed by ListContainer

Source/platform/graphics/paint/DrawingDisplayItem.h

Index: Source/platform/graphics/paint/DrawingDisplayItem.h
diff --git a/Source/platform/graphics/paint/DrawingDisplayItem.h b/Source/platform/graphics/paint/DrawingDisplayItem.h
index 8b4b46674c109145df0a46bb5dafe0cb9d1e0305..6400dc2c897480637a21fdf488e758f271d0d8a1 100644
--- a/Source/platform/graphics/paint/DrawingDisplayItem.h
+++ b/Source/platform/graphics/paint/DrawingDisplayItem.h
@@ -22,37 +22,20 @@ public:
     };
 #endif
 
-    static PassOwnPtr<DrawingDisplayItem> create(const DisplayItemClientWrapper& client
-        , Type type
-        , PassRefPtr<const SkPicture> picture
-#if ENABLE(ASSERT)
-        , UnderInvalidationCheckingMode underInvalidationCheckingMode = CheckPicture
-#endif
-        )
-    {
-        return adoptPtr(new DrawingDisplayItem(client
-            , type
-            , picture
-#if ENABLE(ASSERT)
-            , underInvalidationCheckingMode
-#endif
-            ));
-    }
+    DrawingDisplayItem() : m_picture(nullptr) { }
 
-    DrawingDisplayItem(const DisplayItemClientWrapper& client
-        , Type type
-        , PassRefPtr<const SkPicture> picture
+    void setNew(PassRefPtr<const SkPicture> picture
 #if ENABLE(ASSERT)
-        , UnderInvalidationCheckingMode underInvalidationCheckingMode
+        , UnderInvalidationCheckingMode underInvalidationCheckingMode = CheckPicture
 #endif
         )
-        : DisplayItem(client, type)
-        , m_picture(picture && picture->approximateOpCount() ? picture : nullptr)
     {
+        if (picture && picture->approximateOpCount())
+            m_picture = picture;
 #if ENABLE(ASSERT)
         m_underInvalidationCheckingMode = underInvalidationCheckingMode;
 #endif
-        ASSERT(isDrawingType(type));
+        ASSERT(isDrawingType(type()));
     }
 
     virtual void replay(GraphicsContext&);