WIP for display item list backed by ListContainer

Source/platform/graphics/paint/TransformDisplayItem.h

Index: Source/platform/graphics/paint/TransformDisplayItem.h
diff --git a/Source/platform/graphics/paint/TransformDisplayItem.h b/Source/platform/graphics/paint/TransformDisplayItem.h
index ebf36ac25c0e909c6b41265431b972d9160dec79..be0ffbf49496c2ed006425d087ec9ed1f62f1322 100644
--- a/Source/platform/graphics/paint/TransformDisplayItem.h
+++ b/Source/platform/graphics/paint/TransformDisplayItem.h
@@ -12,17 +12,12 @@
 namespace blink {
 
 class PLATFORM_EXPORT BeginTransformDisplayItem : public PairedBeginDisplayItem {
-    WTF_MAKE_FAST_ALLOCATED(BeginTransformDisplayItem);
 public:
-    static PassOwnPtr<BeginTransformDisplayItem> create(const DisplayItemClientWrapper& client, const AffineTransform& transform)
+    void setNew(const AffineTransform& transform)
     {
-        return adoptPtr(new BeginTransformDisplayItem(client, transform));
+        m_transform = transform;
     }
 
-    BeginTransformDisplayItem(const DisplayItemClientWrapper& client, const AffineTransform& transform)
-        : PairedBeginDisplayItem(client, BeginTransform)
-        , m_transform(transform) { }
-
     virtual void replay(GraphicsContext&) override;
     virtual void appendToWebDisplayItemList(WebDisplayItemList*) const override;
 
@@ -31,20 +26,11 @@ private:
     virtual void dumpPropertiesAsDebugString(WTF::StringBuilder&) const override final;
 #endif
 
-    const AffineTransform m_transform;
+    AffineTransform m_transform;
 };
 
 class PLATFORM_EXPORT EndTransformDisplayItem : public PairedEndDisplayItem {
-    WTF_MAKE_FAST_ALLOCATED(EndTransformDisplayItem);
 public:
-    static PassOwnPtr<EndTransformDisplayItem> create(const DisplayItemClientWrapper& client)
-    {
-        return adoptPtr(new EndTransformDisplayItem(client));
-    }
-
-    EndTransformDisplayItem(const DisplayItemClientWrapper& client)
-        : PairedEndDisplayItem(client, EndTransform) { }
-
     virtual void replay(GraphicsContext&) override;
     virtual void appendToWebDisplayItemList(WebDisplayItemList*) const override;