[Slimming Paint] Blink-side contiguous allocation of display items.

Source/platform/graphics/paint/ClipRecorder.cpp

Index: Source/platform/graphics/paint/ClipRecorder.cpp
diff --git a/Source/platform/graphics/paint/ClipRecorder.cpp b/Source/platform/graphics/paint/ClipRecorder.cpp
index 89471735da5e17201d0753c382e0102209552f18..407fc4c386dc477fd0ce148ebf55e5a7ec6032e6 100644
--- a/Source/platform/graphics/paint/ClipRecorder.cpp
+++ b/Source/platform/graphics/paint/ClipRecorder.cpp
@@ -17,13 +17,13 @@ ClipRecorder::ClipRecorder(GraphicsContext& context, const DisplayItemClientWrap
     , m_context(context)
     , m_type(type)
 {
+    ClipDisplayItem clipDisplayItem(m_client, type, pixelSnappedIntRect(clipRect), operation);
     if (RuntimeEnabledFeatures::slimmingPaintEnabled()) {
         ASSERT(m_context.displayItemList());
         if (m_context.displayItemList()->displayItemConstructionIsDisabled())
             return;
-        m_context.displayItemList()->add(ClipDisplayItem::create(m_client, type, pixelSnappedIntRect(clipRect), operation));
+        m_context.displayItemList()->add(clipDisplayItem);
     } else {
-        ClipDisplayItem clipDisplayItem(m_client, type, pixelSnappedIntRect(clipRect), operation);
         clipDisplayItem.replay(m_context);
     }
 }
@@ -31,13 +31,13 @@ ClipRecorder::ClipRecorder(GraphicsContext& context, const DisplayItemClientWrap
 ClipRecorder::~ClipRecorder()
 {
     DisplayItem::Type endType = DisplayItem::clipTypeToEndClipType(m_type);
+    EndClipDisplayItem endClipDisplayItem(m_client, endType);
     if (RuntimeEnabledFeatures::slimmingPaintEnabled()) {
         ASSERT(m_context.displayItemList());
         if (m_context.displayItemList()->displayItemConstructionIsDisabled())
             return;
-        m_context.displayItemList()->add(EndClipDisplayItem::create(m_client, endType));
+        m_context.displayItemList()->add(endClipDisplayItem);
     } else {
-        EndClipDisplayItem endClipDisplayItem(m_client, endType);
         endClipDisplayItem.replay(m_context);
     }
 }