Blink-side contiguous allocation of display items.

Source/core/paint/LayerClipRecorder.cpp

Index: Source/core/paint/LayerClipRecorder.cpp
diff --git a/Source/core/paint/LayerClipRecorder.cpp b/Source/core/paint/LayerClipRecorder.cpp
index 8ed407eb3a00945912f0a74413a992922bf1cfe9..575ae232e142fbef27068a48aeeb8a9741065b1d 100644
--- a/Source/core/paint/LayerClipRecorder.cpp
+++ b/Source/core/paint/LayerClipRecorder.cpp
@@ -24,16 +24,19 @@ LayerClipRecorder::LayerClipRecorder(GraphicsContext& graphicsContext, const Lay
     , m_clipType(clipType)
 {
     IntRect snappedClipRect = pixelSnappedIntRect(clipRect.rect());
-    OwnPtr<ClipDisplayItem> clipDisplayItem = ClipDisplayItem::create(layoutObject, clipType, snappedClipRect);
-    if (localPaintingInfo && clipRect.hasRadius())
-        collectRoundedRectClips(*layoutObject.layer(), *localPaintingInfo, graphicsContext, fragmentOffset, paintFlags, rule, clipDisplayItem->roundedRectClips());
+    OwnPtr<Vector<FloatRoundedRect>> roundedRectClips;
+    if (localPaintingInfo && clipRect.hasRadius()) {
+        roundedRectClips = adoptPtr(new Vector<FloatRoundedRect>());
+        collectRoundedRectClips(*layoutObject.layer(), *localPaintingInfo, graphicsContext, fragmentOffset, paintFlags, rule, *roundedRectClips);
+    }
     if (!RuntimeEnabledFeatures::slimmingPaintEnabled()) {
-        clipDisplayItem->replay(graphicsContext);
+        ClipDisplayItem clipDisplayItem(layoutObject, clipType, snappedClipRect, roundedRectClips.release());
+        clipDisplayItem.replay(graphicsContext);
     } else {
         ASSERT(m_graphicsContext.displayItemList());
         if (m_graphicsContext.displayItemList()->displayItemConstructionIsDisabled())
             return;
-        m_graphicsContext.displayItemList()->add(clipDisplayItem.release());
+        m_graphicsContext.displayItemList()->createAndAppendIfNeeded<ClipDisplayItem>(layoutObject, clipType, snappedClipRect, roundedRectClips.release());
     }
 }
 
@@ -83,8 +86,7 @@ LayerClipRecorder::~LayerClipRecorder()
         if (m_graphicsContext.displayItemList()->displayItemConstructionIsDisabled())
             return;
         DisplayItem::Type endType = DisplayItem::clipTypeToEndClipType(m_clipType);
-        OwnPtr<EndClipDisplayItem> endClip = EndClipDisplayItem::create(m_layoutObject, endType);
-        m_graphicsContext.displayItemList()->add(endClip.release());
+        m_graphicsContext.displayItemList()->createAndAppendIfNeeded<EndClipDisplayItem>(m_layoutObject, endType);
     } else {
         m_graphicsContext.restore();
     }