WIP for display item list backed by ListContainer

Source/core/paint/LayerFixedPositionRecorder.cpp

Index: Source/core/paint/LayerFixedPositionRecorder.cpp
diff --git a/Source/core/paint/LayerFixedPositionRecorder.cpp b/Source/core/paint/LayerFixedPositionRecorder.cpp
index f823fbc8b0990189d83ef8d750d950d6abbe7afa..0d5e42be7357935850479bfa3b444dfa2f058610 100644
--- a/Source/core/paint/LayerFixedPositionRecorder.cpp
+++ b/Source/core/paint/LayerFixedPositionRecorder.cpp
@@ -26,14 +26,18 @@ LayerFixedPositionRecorder::LayerFixedPositionRecorder(GraphicsContext& graphics
     if (m_graphicsContext.displayItemList()->displayItemConstructionIsDisabled())
         return;
 
-    if (m_isFixedPosition)
-        m_graphicsContext.displayItemList()->add(BeginFixedPositionDisplayItem::create(m_layoutObject));
+    ALLOW_UNUSED_LOCAL(m_isFixedPosition);
+    ALLOW_UNUSED_LOCAL(m_isFixedPositionContainer);
+    ALLOW_UNUSED_LOCAL(m_layoutObject);
+
+    //if (m_isFixedPosition)
+    //    m_graphicsContext.displayItemList()->add(BeginFixedPositionDisplayItem::create(m_layoutObject));
 
     // TODO(trchen): Adding a pair of display items on every transformed
     // element can be expensive. Investigate whether we can optimize out some
     // of them if applicable.
-    if (m_isFixedPositionContainer)
-        m_graphicsContext.displayItemList()->add(BeginFixedPositionContainerDisplayItem::create(m_layoutObject));
+    //if (m_isFixedPositionContainer)
+    //    m_graphicsContext.displayItemList()->add(BeginFixedPositionContainerDisplayItem::create(m_layoutObject));
 }
 
 LayerFixedPositionRecorder::~LayerFixedPositionRecorder()
@@ -44,19 +48,19 @@ LayerFixedPositionRecorder::~LayerFixedPositionRecorder()
     if (m_graphicsContext.displayItemList()->displayItemConstructionIsDisabled())
         return;
 
-    if (m_isFixedPositionContainer) {
-        if (m_graphicsContext.displayItemList()->lastDisplayItemIsNoopBegin())
-            m_graphicsContext.displayItemList()->removeLastDisplayItem();
-        else
-            m_graphicsContext.displayItemList()->add(EndFixedPositionContainerDisplayItem::create(m_layoutObject));
-    }
-
-    if (m_isFixedPosition) {
-        if (m_graphicsContext.displayItemList()->lastDisplayItemIsNoopBegin())
-            m_graphicsContext.displayItemList()->removeLastDisplayItem();
-        else
-            m_graphicsContext.displayItemList()->add(EndFixedPositionDisplayItem::create(m_layoutObject));
-    }
+    //if (m_isFixedPositionContainer) {
+    //    if (m_graphicsContext.displayItemList()->lastDisplayItemIsNoopBegin())
+    //        m_graphicsContext.displayItemList()->removeLastDisplayItem();
+    //    else
+    //        m_graphicsContext.displayItemList()->add(EndFixedPositionContainerDisplayItem::create(m_layoutObject));
+    //}
+
+    //if (m_isFixedPosition) {
+    //    if (m_graphicsContext.displayItemList()->lastDisplayItemIsNoopBegin())
+    //        m_graphicsContext.displayItemList()->removeLastDisplayItem();
+    //    else
+    //        m_graphicsContext.displayItemList()->add(EndFixedPositionDisplayItem::create(m_layoutObject));
+    //}
 }
 
 } // namespace blink