WIP for display item list backed by ListContainer

Source/core/paint/DisplayItemListPaintTest.cpp

Index: Source/core/paint/DisplayItemListPaintTest.cpp
diff --git a/Source/core/paint/DisplayItemListPaintTest.cpp b/Source/core/paint/DisplayItemListPaintTest.cpp
index 4ccac96c24c32f3dfa60ceb578a338fee83cd637..038a9f636e4084fb63b8dc818d8329f504500818 100644
--- a/Source/core/paint/DisplayItemListPaintTest.cpp
+++ b/Source/core/paint/DisplayItemListPaintTest.cpp
@@ -57,7 +57,22 @@ private:
 
 class TestDisplayItem : public DisplayItem {
 public:
-    TestDisplayItem(const DisplayItemClientWrapper& client, Type type) : DisplayItem(client, type) { }
+    TestDisplayItem(DisplayItemClientWrapper& client, Type type)
+    {
+        setClientAndType(client, type);
+    }
+
+    TestDisplayItem(LayoutObject& client, Type type)
+    {
+        DisplayItemClientWrapper clientWrapper(client);
+        setClientAndType(clientWrapper, type);
+    }
+
+    TestDisplayItem(InlineBox& client, Type type)
+    {
+        DisplayItemClientWrapper clientWrapper(client);
+        setClientAndType(clientWrapper, type);
+    }
 
     virtual void replay(GraphicsContext&) override final { ASSERT_NOT_REACHED(); }
     virtual void appendToWebDisplayItemList(WebDisplayItemList*) const override final { ASSERT_NOT_REACHED(); }