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

Source/platform/graphics/paint/DrawingRecorder.cpp

Index: Source/platform/graphics/paint/DrawingRecorder.cpp
diff --git a/Source/platform/graphics/paint/DrawingRecorder.cpp b/Source/platform/graphics/paint/DrawingRecorder.cpp
index 34b43b3b99dd704803043d5ba30baaffd5a1f975..ba6c1374551c349e6e3ee80f2d5b2a31e5713ef0 100644
--- a/Source/platform/graphics/paint/DrawingRecorder.cpp
+++ b/Source/platform/graphics/paint/DrawingRecorder.cpp
@@ -91,13 +91,14 @@ DrawingRecorder::~DrawingRecorder()
                 m_displayItemClient.debugName().utf8().data());
         }
 #endif
-        m_context.displayItemList()->add(CachedDisplayItem::create(m_displayItemClient, DisplayItem::drawingTypeToCachedType(m_displayItemType)));
+        CachedDisplayItem cachedDisplayItem(m_displayItemClient, DisplayItem::drawingTypeToCachedType(m_displayItemType));
+        m_context.displayItemList()->add(cachedDisplayItem);
     } else {
-        OwnPtr<DrawingDisplayItem> drawingDisplayItem = DrawingDisplayItem::create(m_displayItemClient, m_displayItemType, m_context.endRecording());
+        DrawingDisplayItem drawingDisplayItem(m_displayItemClient, m_displayItemType, m_context.endRecording());
 #if ENABLE(ASSERT)
-        drawingDisplayItem->setUnderInvalidationCheckingMode(m_underInvalidationCheckingMode);
+        drawingDisplayItem.setUnderInvalidationCheckingMode(m_underInvalidationCheckingMode);
 #endif
-        m_context.displayItemList()->add(drawingDisplayItem.release());
+        m_context.displayItemList()->add(drawingDisplayItem);
     }
 }