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

Source/platform/graphics/paint/DrawingRecorder.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "platform/graphics/paint/DrawingRecorder.h"
 
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/graphics/GraphicsContext.h"
 #include "platform/graphics/GraphicsLayer.h"
@@ skipping 73 matching lines @@
 #endif
 
     if (m_canUseCachedDrawing) {
 #ifndef NDEBUG
         RefPtr<const SkPicture> picture = m_context.endRecording();
         if (picture && picture->approximateOpCount()) {
             WTF_LOG_ERROR("Unnecessary painting for %s\n. Should check recorder.canUseCachedDrawing() before painting",
                 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);
     }
 }
 
 } // namespace blink