Replace OwnPtr with WTF::Optional for optional recorders.

Source/core/paint/BlockPainter.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 "core/paint/BlockPainter.h"
 
 #include "core/editing/FrameSelection.h"
 #include "core/frame/Settings.h"
 #include "core/layout/LayoutFlexibleBox.h"
 #include "core/layout/LayoutInline.h"
 #include "core/page/Page.h"
 #include "core/paint/BoxClipper.h"
 #include "core/paint/BoxPainter.h"
 #include "core/paint/DeprecatedPaintLayer.h"
 #include "core/paint/InlinePainter.h"
 #include "core/paint/LayoutObjectDrawingRecorder.h"
 #include "core/paint/LineBoxListPainter.h"
 #include "core/paint/PaintInfo.h"
 #include "core/paint/ScopeRecorder.h"
 #include "core/paint/ScrollRecorder.h"
 #include "core/paint/ScrollableAreaPainter.h"
 #include "platform/graphics/paint/ClipRecorder.h"
+#include "wtf/Optional.h"
 
 namespace blink {
 
 void BlockPainter::paint(const PaintInfo& paintInfo, const LayoutPoint& paintOffset)
 {
     PaintInfo localPaintInfo(paintInfo);
 
     LayoutPoint adjustedPaintOffset = paintOffset + m_layoutBlock.location();
 
     PaintPhase originalPhase = localPaintInfo.phase;
@@ skipping 145 matching lines @@
         return;
     }
 
     if (paintPhase == PaintPhaseClippingMask && m_layoutBlock.style()->visibility() == VISIBLE) {
         BoxPainter(m_layoutBlock).paintClippingMask(paintInfo, paintOffset);
         return;
     }
 
     {
         PaintInfo scrolledPaintInfo(paintInfo);
-        OwnPtr<ScrollRecorder> scrollRecorder;
+        Optional<ScrollRecorder> scrollRecorder;
         if (m_layoutBlock.hasOverflowClip()) {
             IntSize scrollOffset = m_layoutBlock.scrolledContentOffset();
             if (m_layoutBlock.layer()->scrollsOverflow() || !scrollOffset.isZero()) {
-                scrollRecorder = adoptPtr(new ScrollRecorder(*paintInfo.context, m_layoutBlock, paintPhase, scrollOffset));
+                scrollRecorder.emplace(*paintInfo.context, m_layoutBlock, paintPhase, scrollOffset);
                 scrolledPaintInfo.rect.move(scrollOffset);
             }
         }
 
         if ((paintPhase == PaintPhaseBlockBackground || paintPhase == PaintPhaseChildBlockBackground)
             && m_layoutBlock.style()->visibility() == VISIBLE
             && m_layoutBlock.hasColumns()
             && !paintInfo.paintRootBackgroundOnly()) {
             LayoutObjectDrawingRecorder recorder(*paintInfo.context, m_layoutBlock, DisplayItem::ColumnRules, bounds);
             if (!recorder.canUseCachedDrawing())
@@ skipping 300 matching lines @@
         LayoutBlock* block = flow->containingBlock();
         for ( ; block && block != &m_layoutBlock; block = block->containingBlock())
             accumulatedPaintOffset.moveBy(block->location());
         ASSERT(block);
         InlinePainter(*flow).paintOutline(info, accumulatedPaintOffset);
     }
 }
 
 
 } // namespace blink