WIP for display item list backed by ListContainer

Source/core/paint/SVGMaskPainter.cpp

Index: Source/core/paint/SVGMaskPainter.cpp
diff --git a/Source/core/paint/SVGMaskPainter.cpp b/Source/core/paint/SVGMaskPainter.cpp
index 0096a38592c90d0bde4feede2c2b96d16fcb42b6..e64f17006bc82253577d15dacbbf4bfecf2bfa6f 100644
--- a/Source/core/paint/SVGMaskPainter.cpp
+++ b/Source/core/paint/SVGMaskPainter.cpp
@@ -28,15 +28,15 @@ bool SVGMaskPainter::prepareEffect(const LayoutObject& object, GraphicsContext*
     if (paintInvalidationRect.isEmpty() || !m_mask.element()->hasChildren())
         return false;
 
-    if (RuntimeEnabledFeatures::slimmingPaintEnabled()) {
-        ASSERT(context->displayItemList());
-        if (context->displayItemList()->displayItemConstructionIsDisabled())
-            return true;
-        context->displayItemList()->add(BeginCompositingDisplayItem::create(object, SkXfermode::kSrcOver_Mode, 1, &paintInvalidationRect));
-    } else {
-        BeginCompositingDisplayItem beginCompositingContent(object, SkXfermode::kSrcOver_Mode, 1, &paintInvalidationRect);
-        beginCompositingContent.replay(*context);
-    }
+    //if (RuntimeEnabledFeatures::slimmingPaintEnabled()) {
+    //    ASSERT(context->displayItemList());
+    //    if (context->displayItemList()->displayItemConstructionIsDisabled())
+    //        return true;
+    //    context->displayItemList()->add(BeginCompositingDisplayItem::create(object, SkXfermode::kSrcOver_Mode, 1, &paintInvalidationRect));
+    //} else {
+    //    BeginCompositingDisplayItem beginCompositingContent(object, SkXfermode::kSrcOver_Mode, 1, &paintInvalidationRect);
+    //    beginCompositingContent.replay(*context);
+    //}
 
     return true;
 }
@@ -55,18 +55,18 @@ void SVGMaskPainter::finishEffect(const LayoutObject& object, GraphicsContext* c
         drawMaskForLayoutObject(context, object, object.objectBoundingBox(), paintInvalidationRect);
     }
 
-    if (RuntimeEnabledFeatures::slimmingPaintEnabled()) {
-        ASSERT(context->displayItemList());
-        if (!context->displayItemList()->displayItemConstructionIsDisabled()) {
-            if (context->displayItemList()->lastDisplayItemIsNoopBegin())
-                context->displayItemList()->removeLastDisplayItem();
-            else
-                context->displayItemList()->add(EndCompositingDisplayItem::create(object));
-        }
-    } else {
-        EndCompositingDisplayItem endCompositingContent(object);
-        endCompositingContent.replay(*context);
-    }
+    //if (RuntimeEnabledFeatures::slimmingPaintEnabled()) {
+    //    ASSERT(context->displayItemList());
+    //    if (!context->displayItemList()->displayItemConstructionIsDisabled()) {
+    //        if (context->displayItemList()->lastDisplayItemIsNoopBegin())
+    //            context->displayItemList()->removeLastDisplayItem();
+    //        else
+    //            context->displayItemList()->add(EndCompositingDisplayItem::create(object));
+    //    }
+    //} else {
+    //    EndCompositingDisplayItem endCompositingContent(object);
+    //    endCompositingContent.replay(*context);
+    //}
 }
 
 void SVGMaskPainter::drawMaskForLayoutObject(GraphicsContext* context, const LayoutObject& layoutObject, const FloatRect& targetBoundingBox, const FloatRect& targetPaintInvalidationRect)